While I agree and I have done more than one rewrite / cleanup of messy codebases quite successfully with LLMs in the past few months, I can assure you plenty of people are still using the latest models to accrue technical debt faster than I thought was ever possible. The model "taste", assuming it has one, does not survive bad instructions
People refuse to accept that there's more bad code/behavior/people that AI will empower and amplify than good.
the models have gotten very good at doing what you ask. if you ask for changes that will accrue tech debt, you'll get it. if you ask for changes that pay down that debt, you'll get it.
Like real life, you want to accrue debt strategically.
When you're experimenting, vetting ideas, mapping out the requirements, exploring solutions, then technical debt keeps churn cheap.
e.g. You don't want to overly commit to static types that keep "impossible state unrepresentable" too early on since you aren't even sure yet what impossible state looks like in the system.
So we regard debt repayment as some sort of transformation we'll do in the future that never comes because it's hard and expensive, but not to LLMs.