As far as I'm aware, there's never been a key command to create or destroy desktops, but that shouldn't impact you at all.
Simply create as many as you are likely to need, rather than destroy each after you've done with it. "Spare" Desktops/Spaces in themselves don't impact your environment at all, they can even help.
If you set up key commands, in System Prefs > Keyboard > Shortcuts > Mission Control you can instantly get to any of them. Every time you create a new Space, a new key command Ctrl ⌃ [num] is created for it - but it is not enabled by default. Creating & destroying Spaces constantly will mean these never become permanently enabled.
Once created, you can assign specific Apps to specific Spaces. This is a major work-flow benefit, no longer do you have apps fighting for screen space.
To move an app to a Space, first switch to that Space then launch the App. Then right click it in the dock > Options > This Desktop [You'll note Apple use the terms Desktop & Space interchangeably]
One you have Apps assigned to Spaces, then all you need do to reach that App is hit the key command assigned to its Space number.
For a bit more detail, see https://apple.stackexchange.com/questions/179376/what-is-an-efficient-way-for-developers-power-users-to-use-osx-window-manageme
Note that Fullscreening Apps removes any & all benefit that Spaces can supply. Fullscreens have no Space number & cannot be assigned a key command. For this [& many other reasons] I would never advise using Fullscreen for anything other than a temporary measure, such as watching a video, etc.