Yes, I noticed that too. Basically, they’ve reduced the use of Liquid Glass in some areas and replaced it with this blur effect in certain spots to improve readability… they seem a bit confused to me.
For example, in Safari it doesn’t make sense — the liquid glass was useful for viewing the page in full screen, but with this change it’s like the background part is no longer visible.
I know many users had complained about readability, and I didn’t like it at first either, but I think it was just a matter of getting used to it — which, in fact, I eventually started to appreciate.