Nah, single player games won’t become scarce. Actually, it’s the key to success, really.
As I say time and time again, Fortnite, Warzone and GTA Online already capitalized on the live service market. People are not dropping those for some random copycat like Suicide Squad or whatever.
Single player games are events on itself. BG3 was huge, TotK was huge, Ragnarok, Spiderman, Hogwarts, hell, even smaller stuff like Jedi Survivor got engagement.
Gaming living through the phase that Hollywood was living a couple of years ago: thinking streaming and services were the key. Then came Barbenheimmer and they understood that people are willing to go to the cinema if the movie’s good.
Same thing will happen for gaming: they’ll fail and fail at live service stuff until something like BG3 comes out and wipes the floor.