Single player games were never ‘dead’, there was just too much of an over saturation of mediocre/average joe single player games with not enough good ones being made for a while, which made Microsoft look at the data without any context and assume the genre was dying. It never was, in terms of sales potential. It only ‘died’ in the sense that appealing ones were few and far between, and that was technically the fault of developers.
However, it IS true that multiplayer games have more sales potential than single player games. And that’s part of the reason fewer good ones were being made in the first place. The best developers want to maximize sales and popularity, so most of them put a lot of effort into including multiplayer or even completely focusing on that. Absolutely understandable, but it created this false impression that single player games lost their sales potential. They didn’t, they just stopped being worked on as much by the AAA developers, and sometimes they were overshot in production costs. (Tomb Raider, etc)
Multiplayer has always had more sales potential, and it’s just better and less risky to make more games like that, but good single player games will always have high sales potential, provided they’re being made and made by good developers. Just because they have less potential doesn’t mean they have bad or weakening potential. They’re just as strong or stronger, they just don’t have AS much potential as multiplayer, and they never have. Which makes multiplayer games a bit safer.
.....all that said, UC4 still has multiplayer in it rofl So it doesn’t really fit in with this discussion as much, even if it isn’t the main focus of the game. The sort-of pioneers proving that single player alone can still stand strong are games like Horizon, Zelda, etc