OK, I am starting to think that this is just a knee-jerk reaction to many of the Big Sur changes.
These changes aren't even definitive, in previous transitions Apple tends to experiment with it before settling for a design. Like every first version/iteration of a design, they are prone and bound to have changes in upcoming OS versions. Give time to them.
I personally have ZERO issue with the Big Sur UI changes. In fact, I like them, and that is my professional opinion. There is very little details about their UI/UX changes to complain about:
- 2D Dock, I understand they wanted parity with iOS, although I think that it should've been the other way around and keep the 3D Dock (subjective opinion, but they should at least give that option to the user);
- Transparent menubar changing according to the wallpaper (again subjective opinion, but again at least should've given to the users the option to choose between no transparency, transparency and the dark/white modes no matter which was the wallpaper);
- The system security is blocking me from changing the /Apps and /Users/Bruno/Documents folders icon for no apparent reason. Before Catalina I could do that;
Other than that, I have nothing to complain about Big Sur design. Look at Ubuntu "Hirsute Hippo" Gnome, they're doing pretty much the same design. Many linux distros are following the exact same design, not just Apple. Recently, Microsoft with their evolution of Metro (called Fluid design now) has some pretty nice icons and is adopting a flat, but fluid design variation too. I am pretty comfortable in all three UI/UX experiences, although I do not like Windows 10 at all for its surprise auto-update moments and data collection/telemetry data being sent to M$.
Regarding menu transparency, toolbars, window titlebars, buttons, I have absolutely zero complaints. You're just knee-jerk reacting to these changes with subjective opinion not based on facts, like other user suggested before. You don't like it, you made it very clear. You prefer the things how they were before - I understand your reaction, my dad has the exact same reaction. But instead of bitching about, what is he doing? trying to adapt to the changes, while considering a move back to Windows or a move to Linux.
There's nothing you can do about except downgrade to Catalina or any other older version. You should be thankful that you have choice - You can stay on it and adapt, you can downgrade, move to Linux and customize it your way (considering how much you're bitching about the design, this is probably your best choice) or move back to CRAPindows 10, since older CRAPindows are now pretty much EOL and officially not supported.
Move along with the times, dude. Yes, flat design has had its heyday, and I am pretty sure you will bitch much more if Apple decides to adopt the neuomorphism. God forbids them, I hate this new weird web design trend and prefer Metro/Flat designs because I am a minimalist professional UI/UX Designer and this style is what my clients ask for on their projects.
Bitching about the traffic siginal buttons or window titlebars design 24/7 is not going to change anything for you. Do something about it instead. That is my advice to you.