Nobody cares about costs until they pay them themselves.

Regarding code quality and tech debt, it's sensible not to care if it doesn't lead to anything observable. Do you really care of some "bad" code somewhere that hasn't changed for 5 years but keeps working fine, and has no new requirements?

On the other hand, if you work on an active codebase where fixing one bug inevitably leads to another, maybe it's worth asking whether the code quality is simply too low to deliver on the product expectations.

It's not even obvious to me in which direction coding agents move the needle. Do you want higher quality, at least at a higher (design) level, when you heavily use agents, so that you know know the mess will at least compartmentalized, and easier to deal with later if needed? Or do you just assume the agent will always do the work and you won't need to dig into the code yourself? So far I've mostly done the former, but I understand that for some projects, the latter can make sense.