There are many techniques for making a closed-source binary harder to reverse engineer: polymorphism, symbol stripping, code encryption, packing, and so on. Closed-source binaries at least stand a chance of being effectively obfuscated, unlike open-source code.
and those measures have always been merely annoyances. except for the VM methods which impact performance significantly.
now none of those methods matter as you can just instruct an LLM to bang its head against the wall until the wall breaks.
They still matter in the sense that they impose a cost. In other words, they buy time, which is all the users need before updating.
I'm not sure if the cat and mouse game resolves clearly one way or another. Since the obfuscation can be hardened against LLMs during development.