https://www.zdnet.com/article/recreatin ... ctivities/
These parts are what causes some confusion with/for KDE users certainly did me at first, years ago
This from the above link is what I don't use activities ,, could not be bothered setting up when instead use 6 workplaces/named and always same set-up, each for just one set of chores each, wallpapers don't bother me what they are, just get the work done.
But do take the time to read the full article there could be some info in there, that would/might be of help.The next step was to create the six virtual desktops, and give each one the appropriate wallpaper. That was where I ran into the first (and biggest) problem. It turns out that virtual desktops have been (at least temporarily) depreciated in KDE5, and you can no longer have different wallpapers, or different widgets, between different virtual desktops.
I don't want to get into a long technical, political or religious discussion of this decision, so I am simply going to say that if you want more information, there are two major discussions of it in the KDE bugtracking system (yes, it was originally reported as a bug). Refer to Bug 343246 and Bug 341143 for more information and discussion than you are likely to want about this "feature". For purposes of this post I am simply going to say that it is what it is, and I will try to work with what is available to achieve my objective.
So now I needed to create six Activities, rather than six Virtual Desktops. That was easily enough done through the Activities Manager, which can be accessed by right-clicking on the desktop or with the Alt-D Alt-A key sequence, or with Meta-Q. Each new Activity was given a name, description and an icon. I was also able to change the information for the Default Activity by simply clicking on its configure button.
Edit
A lot of my software/if not most will only open on the dedicated workspace
