I never said anything about "random" missions, and I never said anything about "infinite". I meant: no pressure to push forward because you have an AI slowly eating away at your brain.
I mean "non-linear". Create, saaay, 10 mission chains, each of which contains 3-5 indivudal missions and 2-3 different outcomes. You can do them in any order. You can choose to play individual missions or not. Might be really cool to have certain missions change if you've done other missions first.
And, the player can freely level up and complete things like the street-racing stuff, the prize-fighter chain, the Cyberpsycho missions, the NCPD quests, etc. One of the big reasons I suggest this is because I like the way the main quest plays out when handled in an uninterrupted way. (I didn't handle my game that way -- had something like 110 hours when I was done with the playthrough, but I could easily play back the story in my mind and realize, wow -- that would work really well as a film or miniseries.)
So, I think it would work well as: Intro --> freeform exploration of Night City coupled with snooping, thieving, gigs, leveling up, etc. --> player discovers a bunch of standalone quests, all of which tell small, contained stories in and of themselves --> player-triggered endgame to meet Dex and begin the heist --> main quest plays out seamlessly and the game ends.
(And/or, if this helps to make sense of it: If you never call Jackie to be like, "This thing you're working on -- let's do it," but instead complete all of the new, non-linear content, you'll get the call from Jackie to meet you downstairs.)