I find it incredibly confusing and pointless when I'm alt-tabbing to an application, but then "nothing happens" (e.g. only the menu bar changes but the app has

I find it incredibly confusing and pointless when I'm alt-tabbing to an application, but then "nothing happens" (e.g. only the menu bar changes but the app has no windows open - I really can't understand why such ancient "MacOS-isms" are still carried along - like, what's the point of a UI application lingering around when there's no UI?) Disclaimer: Mac is my main platform since around 2010, before that Windows, and before that Amiga - one would think that more than a decade would be enough to acclimate, but the whole application model on Mac still feels weird :)