Compilation doesn't necessarily need strict checks, it's really just translating source code into machine code. It happens to be the case that we mostly do both

Compilation doesn't necessarily need strict checks, it's really just translating source code into machine code. It happens to be the case that we mostly do both using the same tools because compilers need to have a good understanding of type systems to do their job well, but it's not a strict requirement. A great counter example is esbuild, which will compile TypeScript but not perform actual type checks for performance reasons. This is possible because TypeScript types have no representation at runtime. and are really only a development tool.