The copout answer is it depends. I've debugged sloppy code in React both before and after LLMs were commonly used. I've also debugged very well-written custom frameworks before and after LLMs.

I think with proper guardrails and verification/validation, a custom framework could be easier to maintain than sloppy React code (or insert popular framework here).

My point is that as long as we keep the status quo of how software is built (using popular tools that male it fast and easy to build software without LLMs that often were unperformant), we'll keep heading down this path of trying to solve the problems of frameworks instead of directly solving the problems with our app.

(BTW, it was your comment to my comment that inspired my comment, talk about meta! https://news.ycombinator.com/item?id=47512874 )