There's absolutely no way I'd share my codebase with some fly-by-nighter ~crypto~ AI company, but the codebase I work on is upwards of 60 million lines of code so I doubt any "AI" solution would come close to being useful.
At 60 Mloc? Sure, for now I'd agree. An AI needs to use other tools to handle that kind of size, it doesn't (practically) work so well if you try to hold the whole thing in context.
And while tool use is being worked on, the results I've seen are are the "that's an interesting tech demo" level rather than the mind-blowing change when InstructGPT demonstrated the ability for a language model to generate any meaningful code at all from natural language instruction.