The ballooning costs are in part due to the inflating bloat they keep trying to stuff into every game. Not every bloody game needs a crafting or a skill system, nor does every game need 100+ sidequests throughout the entire campaign.

I think some studios were also banking on investors fronting them for a long time, based on player numbers and playtime, which was never seriously going to hold in the long run. Players can only be led around on a leash in so many games for so long before they just get sick and tired of being denied actual fun in the games they're purchasing.