macOS annoyingly puts fullscreen videos in a new "space" When watching a video on YouTube (or any other streaming service) – I use mainly Safari, sometimes Chrome, with the same result – when I switch to fullscreen, the video goes fullscreen in a new "Space" (virtual screen).

I'm not interested in virtual spaces in general, I've always found it to be a very un-Mac-y way to work. But in the case of videos, it's pretty annoying. Let's say I get a notification (mail, IM, anything) and want to quickly check it. I command-tab to the app that sent me the notification and instead of just superimposing to window on top of the video (as it does on Windows and as it did in earlier versions of Mac OS X), the sound continues playing, the video vanishes and I get that useless screen:



I then have to click to exit full screen and double click again to get the full screen back (I'm sure there are other ways, with gestures and all, but it's just annoying).

Is there a way to revert to a sensible (à la Windows, or previous OS X versions) on recent macOS versions? I know VLC can do it, so it is theoretically possible, but did Apple hide a system setting somewhere to change that behaviour? If not, is there an app that does it?
Have you tried adjusting the settings related to this in System Preferences > Mission Control?

The first checkbox there lets you disable automatic grouping of windows and there are other related options there too. You can also totally disable having multiple screens there. 

I'm not sure if you're using macOS mojave and this is no longer a feature. Also this is the one gesture that I use..dragging from one side of the trackpad to the other with 3 fingers.