It seems obvious to me that liquid glass is no designer's idea of a good UI. It's a business move to force developers to support the upcoming iGlasses where transparency is actually necessary.

Perhaps Apple is willing to accept that most macOS users will enable "reduce transparency" so long as devs implement support for transparency.

But there is another explanation making the rounds, possibly a conspiracy theory. Some people claim that Apple is doing this to make cross-platform technologies look obsolete and hard to implement.

If there's any truth to this, it's a terrible idea that could easily backfire. People could get used to there not being a consistent platform look and feel. Like on Windows, "native" could lose its meaning.

Whatever Apple promotes as "native" could become just another style among many.