Other people have written more extensive guides than I have, but I'll give a quick summary on what I think you might need to do, as well as what questions you need to ask yourself.
First and foremost, you need to ask yourself what are you actually aiming for? Some genres perform better than others, and over time genres shift in popularity. A common response you'll see is, "Write in a popular genre", which is bad advice for most people. The popularity of the genre only really determines the ceiling for the number of readers you can get. Unpopular genres can still garner hundreds of readers. Changing what genre you are writing won't change the fundamental issue you're likely running into.
So, what can you draw from this first question? You need to pick what you want and determine what success looks like within that market, or what success looks like to you. I'm not saying you need to be content with some arbitrary number when you might eventually reach it, just that being aware of limitations in a market is important so you don't have unrealistic expectations.
With that out of the way, lets look at the second thing. Looking at your profile, there are a few completed and a few incomplete stories. None of which are breaching 100 chapters. By nature of the way most writing websites work (searching by books), your discoverability will be low. Someone already mentioned consistency, which is true, but doesn't paint a full picture. Consistency can be broken into two parts. Predictability for readers, and exposure on the front page to the same audience in recent postings.
The fact of the matter is, 95% of readers don't go to the author profile to see other works by them. When they finish a book they liked, they just go back to search and find something else. By having relatively low chapter counts (I know that 50 seems like a lot, but it really isn't in the grand scheme of things), you're essentially restarting the climb every time, and not reaching the first rest point where you start to garner readers long term. This links back to the first question. If you prefer to write these sorts of short(er) stories, it will hurt your reader count. I'd argue that you could probably keep your style of writing by configuring your works into more of an anthology, where some central theme is used (think horror anthologies), where you can separate the books in volumes (in chapter titles), and keep them all as a central series. That would help discoverability, but it might not work for you. It just depends on what style your writing follows, and how much you are willing to limit your own design space.
Consider that most series don't actually start garnering larger reader counts until after 70-100 chapters, and you can see where your problem might be occurring.
Third, and this may not apply as I haven't actually read any of your works, sometimes plots are simply too generic or inauthentic. Inauthenticity is something readers can smell from miles away. This again loops back to the first point, but if you hate isekai and LitRPG, even if you attempt to write one just because it is popular, it's very likely that most readers will turn away from it because of that inauthentic engagement. It'll leak through. Write what you enjoy writing. It makes it easier to write and keep a schedule that way as well. Far too often I see people encourage others to write things they don't like because they are popular genres. Every genre has a learning curve involving tropes and archtypes that readers expect. Encouraging people to write something they aren't familiar with is like telling someone who says "I want to earn more money" to just go get a job as a stock broker or CEO, since they make a lot of money. It lacks the nuance that you have to read and learn about the genre first. Sure, they can go to school to learn business practices, then earn more money, but fundamentally that isn't really what the person was asking for. Realistically, they should get advice on asking for raises and looking for ways to improve their existing skills for promotions.
That brings it together as the third point - Really focus on honing your skills and determining what you want YOUR stories to convey. Write the stories you want to, but begin focusing on what you can improve about your own writing. Grammar? Flow? Plot hooks? Cliff Hangers? These are things you can work consciously towards improving. Every author can (and should! Successful or not!) focus on improving their fundamentals at all times.
I hope this helps, even if it is a bit long winded.
