I think MacOS would be much more unusable without alt-tab, like this app is a critical piece of software that has to be installed on any MacOS machine I'm using. But it does sometimes miss a window, like it doesn't show up in the window list in alt-tab even though it is open. And then I have to use the three finger swipe up thing to find it. Not a huge deal but occasionally annoying, and I assume it is because they are limited in the access they have to this information, which Apple could make available if they wanted, but have decided not to.