Earlier quoted context omitted.
I mean to be fair, (1) there are replacements, AltTab and Switcher for example, and (2) why replace ot touch something that isn't broken? Cmd+Tab is supposed to switch to the next open window, and it does exactly that.
No, Cmd+Tab switches to the next application. This is what people get surprised and annoyed by. I've been using Mac for 15 years now and I find it super awkward to switch between windows within an app. On my machine it's Cmd ` or something strange like that. This is also doubly bound sometimes, such that I can only cycle forwards OR backwards. Complete mess.
And yes to switch between windows of the same application it's Cmd+Shift+´. Not the most intuitive, but I feel it should not be combined, because that would mess up the sequence massively. If I want to switch Terminal windows, I don't want to do Cmd+Tab and then manually look through all 15 window icons to select.
Like, IMO the status quo is perfect. Sure, you gotta get used to Cmd+Shift+´, but try to do it for a week, and then it's perfectly natural.