You're right, the best selling games have been single-player focused. So why has Ubisoft, EA, Square Enix, ActivisionBlizzard, Warner Bros, and Sony Interactive been pushing to jump on the recent extraction shooter trend? Hell, find me a triple A publisher that does not have a live-service game being maintained, I'll wait.
If you're argument is that AAA is not wasting millions of dollars on chasing trends, you'll have to find more evidence than all their projects being failures.