I actually like the command+tab behavior, and miss it when I use Windows.
I'll explain: if you have a lot of windows open, I think it's nice to silo them. When I have ten Firefox windows and six Sublime windows and three iTerm windows, and a few other random applications, it's generally easier to go first to the app I want and then find the window inside it, rather than always having to shuffle through 19 different windows at the top-level.
This is probably a matter of personal preference and habit, and you can make a good case for either behavior. I just don't think macOS' behavior is obviously worse... only different.
It's nice to silo windows when you have lots open, but I think grouping all browser windows together is not a sensible way to do it. Some browser windows go with my IDE, some with spreadsheets, some terminals, etc. Grouping all browser windows (including web apps, email, etc.) because they happen to use the browser is like grouping all windows whose title starts with "A" or something.
This is true, but my Windows experience suggests that the one-set approach to window-switching doesn't help me maintain that grouping. You do get quick switching between recently-used windows, but if I have more than a few (or multiple sets I need to switch between) then they rapidly get jumbled together for me.
What I actually do on macOS, which I felt was too opinionated to mention in my initial comment, is use Spaces (macOS' virtual-desktops feature) to split things up by task. Normally pretty high-level -- a "work" space and a "relaxing" space always exist, but making task-specific ones to focus on is trivial. Then once you're inside a given space, all the tab shortcuts only switch between windows on that space.
You can also get to that directly from the cmd-tab switcher -- if you press up or down while the switcher is open it jumps straight to exposé for the focused app.
If you pin apps to Windows task bar, you can cycle through the windows of the third one with Winkey-3 and so on. Currently daily drive a mac for work, but the above is my preferred way to switch windows on Windows.
I'll explain: if you have a lot of windows open, I think it's nice to silo them. When I have ten Firefox windows and six Sublime windows and three iTerm windows, and a few other random applications, it's generally easier to go first to the app I want and then find the window inside it, rather than always having to shuffle through 19 different windows at the top-level.
This is probably a matter of personal preference and habit, and you can make a good case for either behavior. I just don't think macOS' behavior is obviously worse... only different.