tl;dr: Yes, a self-published ebook is more than enough.
Self-publishing is the future. Let's look at what a publisher can provide you as an author:
1) Promoting your novel for you
2) Selling your novel for you
3) Proof-reading and editing your novel for you.
4) Advance Payments. The way it works is that essentially a publisher buys a book from you, then sells it. Only once the sales royalties have exceeded the advance payment you've received do you actually gain royalties. If your book never clears that advance payment then you are unlikely to be contracted again.
5) Doing all the pricey stuff, like commissioning artwork, printing physical copies and producing audiobooks
There's a sixth one but that doesn't quite count: Writers' Associations. Writers' associations have massive resources of background materials its members can peruse. If you've ever wondered why traditionally published novels tend to be so well-researched, this is it. Now, while being part of a writers' association isn't technically part of being traditionally published, most writers' associations do not accept self-published authors. Or at least they used to. It is entirely possible that this has changed lately. If you're curious about this, I suggest the blog of indie author Ben Reeder, who talks at length about his struggle to join such an association and in the end he managed it only because he found an association for Horror novels that found the success of his zombie series good enough to let him join.
Now let's tackle the rest in order:
1) Any author with an internet connection and a bit of time on their hands can promote their own work better than a publisher can. I have never, EVER found a novel I liked because a publisher promoted it, even back when I actually gave a damn about traditionally published novels. I have, however, found several of my favorites because the authors themselves have put in time and effort promoting their work.
2) Amazon can do the selling. Given how big a success Kindle Unlimited is, your novel being on there is probably more profitable than a publisher selling your book for you ever will.
3) Both proof-reading and editing can be done without being traditionally published. If you're here on Scribble Hub it should be easy for you to find yourself a fan who would be willing to help you out. Hell, you can use your uploads on this site as a form of proof-reading: Let people read it and take their criticisms to heart. I have people pointing out stupid typos to me quite often and I am grateful every single time.
4) If you are not in a hurry to make money with your writing then you do not need advance payments.
5) This is really the sticking point. A good piece of cover art can run you several hundred bucks. And you absolutely cannot skimp on it, either, even if you hate the way people judge books by their cover. However, this can be remedied with AI artwork (at first, you want to get proper artwork eventually) and you can use Patreon and Kickstarter to raise the money for your cover art. Printing physical copies is expensive but these days the vast majority of book sales is digital anyway so you really only lose a few potential readers by refusing to join the Dead Tree Club. Audiobooks are a bigger problem. They are unreasonably expensive to produce, Audible takes an obscene 60% cut of the sales and overall they are at best loss leaders that help you promote the ebooks. However, sites like Podium Audio are doing their best to remedy this, letting you apply for an audiobook and letting them bear the costs. They are taking another large cut of the profits, certainly, but as we've discussed you weren't gonna see much of a profit from your audiobook release anyway.
On top of this there are many other reasons NOT to find a publisher. These are all anecdotal evidence but given that these constitute the majority of my favorite authors I think it's pretty telling:
1) Unless you get contracted by a big publisher it's possible for them to steal your IP, as has happened with Ben Reeder, who had to wage a legal battle that lasted years just to get his The Demon's Apprentice series back.
2) Unless you get contracted by a big publisher it's possible for them to go bankrupt and scarper with what's left of the money, leaving you in the dirt. This has happened to Richard Roberts. There was a time where pirating Roberts' books was the more moral choice because buying them properly would have benefited only a group of thieves who refused to pay him.
3) Some publisher-appointed proof-readers and editors do not give a fuck. Steve McHugh's Hellequin Chronicles are riddled with typos and for two and a half books a major character's name was misspelled. Those novels were traditionally published and therefore traditionally edited. This should not have happened.
4) Some editors will actively sabotage your career. Elliott James' Pax Arcana series starts off weird. You read the first novel and a bit into the book you get a chapter called: Interlude: This Is The Last Interlude I Promise. It's a fascinating little chapter that gives you some desperately-needed background information and worldbuilding and you spend the rest of the book wondering why there was only this one interlude. Then at the end of the book you get a little mock-interview where the author describes that the book used to have like ten of these interludes but his editor made him cut the rest. He didn't have the heart to just delete them so he put them up on his website. And a good thing he did because they do not just tell you a lot about the worldbuilding but they also betray a staggering level of thought that went into this series and by the end they turn downright profound, speculating on the nature of god and the universe. But this isn't irrelevant background information. Book 1 makes sense without them, book 2 makes a little more sense if you've read them, book 3 makes a lot more sense if you've read them and book 4 is absolutely indecipherable without them. And I'm pretty sure that this editor meddling is the reason the series hasn't seen a new installment in six years.
5) Even authors like Benedict Jacka, who are happy with their publisher, get hampered. Jacka has a blog full of interesting articles about writing as a job and the industry as a whole, as well as a ton of articles on his own series' worldbuilding. And one thing I will never forget is his article about his writing schedule. To make a long story short, it takes him roughly three months to write a book. Then he submits the manuscript to his publisher, which turns into a round of edits and rewrites that lasts up to six months. Then, once the book is finally finished, the publisher sits on it for another three months before actually releasing it, leading to him releasing about a book a year. Now, Jacka states that he uses those three months of downtime to relax and take his mind off writing and I suppose that's fair. But if he wasn't stuck in a giant, pointless bureaucracy then the editing process might take less than half a bleeding year every time.
I apologize for the ridiculously long post but I hope it helps make clear my stance on publishers and why you shouldn't care about them.