I think what you are observing has to do with the fundamental Apple culture. Apple is not a monolithic company - it consists of hundreds and hundreds of teams, each with their own culture, secrecy, and work style. What Apple lacks, plain and simple, is quality assurance. Back in the day it was Jobs’ obsession with detail that kept things polished, because he could exert pressure on the teams from the top.
My opinion is that Apple could benefit from introducing transversal teams with focus on coherency, quality assurance, and documentation. Unfortunately, I this would create a cultural conflict with the secrecy and segregated teams. It’s a tough nut to crack.
I am also scriptural about “they should release the OS when it’s ready”. What does it mean to be “ready?” That’s not a way to do business. Apple is very good at executing, the issue is with communication more than anything else.
And finally, while the critical attention is on bugs or incomplete/immature features (like Liquid Glass and its inconsistent applications), let’s not forget that there is also substantial work on the OS foundation that often gets unnoticed. In particular, 26 release introduced some significant changes to the security model and to the kernel. And this stuff works rather well.