Considering how many compromises and problems third party libraries have caused recently, I would say the comparison is apt - if you don't know what you're shipping one day it might explode on you
replyIt's not because with libraries you have a boundary somewhere and can decide to not care what's inside as long as the interface is stable and well designed. The problem of course you need to prioritise building well designed interfaces and decouple components from each other, and that's a skill most developers aren't good at.
replyModels are getting better. Astra for example refactored some code GPT-5.6 Sol wrote and extracted some related functionality in a separate file without prompting.
replyThe models are also becoming very capable of suggesting architecture simplifications, but you need to ask for that, and you probably need some taste in picking from the suggestions, although the default ones are quite decent.