So... infinite memory with instant recall + fast thinking speed.
A great memory is a decent cheat, but not enough to instantly become god.
(1) Information needed isn't available.
(2) Knowledge, even if available, is never really concentrated in one place. People are very good at filling pages with garbage information that dilutes the contents to a point where you spend more time trying to piece together their garbage than learning anything.
(3) Even with all the knowledge in the world available, that knowledge may be imperfect. e.g., as of now, we don't have a general cure for cancer, or a blueprint for efficient general artificial intelligence, or a photonic computer not limited by memory read/write speeds, or a reliable way to detect and interact with "dark matter", or a way to program DNA to make cells do what we want, or...
(4) Even if you have enough thinking speed, you don't have infinite thinking speed. For most mathematical problems you'll encounter in the real world, brute forcing calculations is not viable: the necessary compute can grow much faster than the size of the problem, even if are smart about how you solve it. For more information, search: time complexity programming.
(5) Even with sufficient knowledge, sometimes you're limited by the means you have to apply that knowledge. e.g., you want to design a microchip: you first need a lithography machine, which is complicated to manufacture in a backwards world, which makes your microchip knowledge obsolete until you get your hands on the lithography machine. Or, you need graphene for whatever reason, and for that you know that you need to do some genetic engineering on microorganisms to use them to manufacture the perfect graphene you need. Doing genetic engineering implies having the tools, the knowledge... decoding the organism's genes, knowing how to modify them...
(6) To really achieve god like omniscience and omnipotence, you'll have to understand the world you're in to the most basic element. You'll have to develop a way to see everything to the most minute detail, and to the greatest distance. And you'll have to develop ways to manipulate reality the way you see fit. The journey to this point can be pretty damn long. And until your MC isn't completely omniscient and omnipotent, not everything has to go according to plan, though for a smart MC it is expected for them to have backup plans or expect the deviations and accept the losses. Unless you have a very unexpected situation, a smart MC will not be caught with their pants down. Besides this, even after achieving god like status among peers, is what they achieved really godhood? Can they only destroy, or can they also create? Is everything already explored, or is there still an unexploited infinity of things out of reach? e.g., the universe is composed of 5% mater, 26% dark matter, and 68% dark energy. Your world might have more worlds in other star systems, galaxies, galactic clusters, etc... Parallel dimensions... Parallel timelines... Many Worlds Interpretation of quantum mechanics...
In short, the world is too big for you to even think that you wrote yourself into a corner with just a super-intelligence cheat skill. Whenever you think you know it all, you should try to list all that you don't know. Your arrogance will fizzle away pretty quickly.