I do think, that in the general case, a JIT compiler is required: you can’t make every program fast, without having the ability to synthesize new code based on only-runtime available information. There are many where AOT is more than enough, but not all are such. Note, this doesn’t preclude AOT/hybrid models as pjmlp correctly says.
One stereotypical (but not the best) example would be regexes: you basically want to compile some AST into a mini-program. This can also be done with a tiny interpreter without JIT, which will be quite competitive in speed (I believe that’s what rust has, and it’s indeed one of the fastest - the advantage of the problem/domain here is that you really can have tiny interpreters that efficiently use the caches, having very little overhead on today’s CPUs), but I am quite sure that a “JITted rust” with all the other optimizations/memory layouts could potentially fair better, but of course it’s not a trivial additional complexity.
One stereotypical (but not the best) example would be regexes: you basically want to compile some AST into a mini-program. This can also be done with a tiny interpreter without JIT, which will be quite competitive in speed (I believe that’s what rust has, and it’s indeed one of the fastest - the advantage of the problem/domain here is that you really can have tiny interpreters that efficiently use the caches, having very little overhead on today’s CPUs), but I am quite sure that a “JITted rust” with all the other optimizations/memory layouts could potentially fair better, but of course it’s not a trivial additional complexity.