Been there, done that. I tried the multiplayer in DOS 1 and 2, and the outcome was always something among the lines of "Well, that was amusing to do once, but fuck me if we are going to schedule a recurring appointment to do this on a regular basis across several weeks".
I think it can work depending on your situation. I would love to have D:OS1&2 back during my Uni days - I had a good friend with whom we had lan parties on regular basis. D:OS1&2 is something we would kill for in those days. Tried to run coop playthroughs of BG2, Neverwinter Nights2 and Arcanum, but it just never felt right.
Right now, it's difficult to get a Civ game going from beginning to conclusion, not to mention 80-100 hour RPG. I don't hate D:OS1&2 design, I think there might be audience for it, and I would be in that audience at one point in my life. It's fine if D:OS1&2 aren't for me anymore. I am irritated for BG3 to be designed like that as well, though.
And for many players whenever RPG is completable or not is probably irrelevant. Looking at GOG achievements only 10% of players there completed D:OS2. One or two online sessions seem to be enough for some to declare those games as "BEST RPGs EVER MADE!" looking at steam reviews and playtime.
