Here’s one way to think about the difference between coming up with a formal proof and having something other mathematicians can use: > A clear explanation can be found in Alex Kontorovich’s account of his own learning curve with formalized mathematics. In a nutshell: Mathlib, the dominant Lean library, is a human-curated formalization of an ever-growing fraction of existing human mathematics. It exposes clean APIs a…
Anyone who understands type theory and how theorem provers work? It's sort of akin to saying "how do you know that a massive C++ program that compiles to machine code compiled to the correct machine code that will actually run and it's just not a random string of bits!?!?!", you know because the compilation would have failed otherwise(this is different than saying the program behaves correctly, but that's precisely the difference between formal proofs and compiled programs).
The entire argument both you and Bessis are implying is that mathematics must be human intelligible. But there's absolutely no reason to assume that every mathematical statement must have a human intelligible representation. There is also not reason to assume that if we restrict ourselves to the subset of mathematical statements that are human intelligible that this is of any use.
Just because people who don't want this to be true, and I can understand the motivation, doesn't mean that it isn't still the case.