[xapata]

JITs get to analyze both code and data and optimize for each machine deployed to. A static compiler can only analyze code and the machine used for compilation. If dependencies were pre-compiled, the static compiler won't be able to optimize their relationship with the project. If the machine is changed for deployment.

More information means better optimizations. JITs FTW.

[jcranmer]

JITs also tend to optimize for compilation time over final performance. Doing ahead-of-time superoptimization or polyhedral loop transformation isn't going to happen in a JIT.

[xapata]

There's no restriction on the kind of optimization a JIT can do. Perhaps there's a current implementation tendency. In contrast, ahead-of-time (data- and platform-ignorant) compilers are restricted.