It seems the problem is the solution, and vice versa.
I watch a YouTuber who is homesteading and builds everything. Often times I see him doing things in ways I know will break or fail eventually, but it doesn't matter because he is there and will fix it when it does. You could argue this is a waste of energy, and for a human it might be. For an LLM however I do not think it is.
I also think that if we’re being completely fair here, we have to acknowledge that most codebases that are more than a couple of years old are giant piles of tech debt already even with 100% human code. At least in all of my jobs, none of which were FAANG, nor run by extremely elite engineers. YMMV.
"Oh no! We're making so much money off the massive number of customers we have that we need to redesign our system!"
Most companies never make it to that stage.
Get there to that point, don't fall victim to second system syndrome and spend 3 years on the rewrite, and you'll be fine.