Chris Lattner (the CEO of Modular) was previously the technical lead behind the creation of LLVM, Clang and Swift, all of which were open sourced.

He has a bit of a track record already.

Sure, but at that time he was employed by Apple for example.

Now he's making a for profit company and there's already MAX and MAX Enterprise stuff to not trust that the open source part would be competitive with already great inferencing frameworks for example.