I disagree. You can still do very good money with old-ass gaming concepts, if they are executed well. Look at GTA. That shit hasn't changed significantly since GTA 3, and it's one of the most valuable and profitable gaming IPs ever. Look at fucking Pokemon, the most valuable entertainment IP ever and the games, even though they aren't even "executed well" are selling gangbusters. Look at fucking Dragon Quest. That IP is the definition of "traditional" and it sells well.
The problem that Square Enix has is that the last couple of Final Fantasy games were mid at best. There is a reason why the most profitable thing is FF14, an MMO that has a fundamental game design from WoW people would nowadays call "old". The reason is that FF14 is the only game that executed that design well, aside from WoW. People like and buy well-designed games. And one of the DQ devs (maybe it was Horii himself?) already said that the reason why Square Enix (and others) have trouble capturing a new generation of gamers is mainly because each game takes like 10+ fucking years to make. It's a project management issue.