For those using huge amount of tokens monthly for dev work, why do you need it?

I can't even use 1b a month because I review everything LLMs write.

I even used AI to code my own harness in C and my own VSCode like IDE in C++ (I hated how slow it felt) and I still used under 1b the months where it did most of the coding.

Just wondering how/what these guys claiming to use a full Claude/Codex 20x subscription are burning it on.

Edit: Also, I never use subagents.