IF there will be an editor similar to DOS 2 editor is still not confirmed, but I assume there will be one and I try to ellaborate WHY and HOW there should be one. (consider my humble suggestions as 2 cents)
I am one of these people who messed around in editors more time than in the actual game (like in DOS2) but actually never really finished / published something there. Looking at the industry, you hardly find any games / applications that provide multiplayer AND realtime collaborative editing (multiplayer for editor / modding). I think Modding Scene in DOS2 (comparable to NWN2 in comparision to NWN1) seamed to be less active because the engine asked for more detail so for more work. More than one single person easily can do in her spare time.
Look at
COSPACES.IO, an educational platform developed for kids and students as target group to create 3D spaces with AR and VR functionality. This works cloud based via browser or app. Although this platform is lacking multiplayer, it offers an amazing option to edit and code the levels collaboratively in realtime together. See this short
video (didnt find a better video, maybe i should upload some footage to better illustrate) I am doing workshops with schools and kids as work and my experience letting a group of students work on one map together is amazing.
@LARIAN: Fill the market niche! Consider making the editor cloud-based realtime collaborative or short: Make a Multiplayer Building Game. This even could solve the open question how to provide an editor for Stadia subscribers. I am highly confident this would exponentially increase to use of the editor and the creating of maps and mods.