It's not sustainable from the perspective of trend-following, where 20 attempts at a trend bankrupt the studio and one hits the jackpot. From the perspective of the proven track record of a team, it clearly has been sustainable for ND, Santa Monica, Insomniac, etc. I think a brand new team of "veteran industry people" with AAA funding should not try to make The Last of Us 3 on their first game out. If they've made 3 or 4 successful AAA games, then obviously it makes sense to keep pushing the envelope. That's what it means to be on the cutting edge in game development. It doesn't undercut smaller great games like Dredge or Tunic.