So let me get this straight. If you want to create a game studio for a living, not AA or AAA, just a studio with 10-15 devs or something, the ONLY way for you to survive is to make GAAS? You can't exist even as a smaller studio if you stick to single player games, is that what you are saying?
What so difficult to understand in "rules are the same in both worlds"?
What newly created studios would/should target, SP or GaaS, is their choice, there is pros and cons in each choice.
What was written in quoted part is that it's extremely hard to live off indies (indie tier budget, not as independent developer, many mix yhis two). Because indie tier budget games are many and there it a bloodbath, and a lot of devs just die in oblivion, never get a chance to make even a slightest name for themselves. Both in SP and GaaS space (and yes, there is gaas indies too).
Thankfully you are 100% wrong. Game studios can exist and make a lot of money with single player games. All you need to is to stop trying to become the next Ubisoft or Activision or trying to get your own island and massive yacht filled with hookers. You can have a nice, comfortable life as a businessman without being in the billionaire celebrities club.
Some money - yes. A lot of money - no.
Live service games just bigger in both people and money.
You can be WuKong big or even CDPR big, but you'll never be CoD or Mihoyo or Tencent big.
This whole "everything or nothing" line of thinking is unsustainable and needs to die. Most things exist in the in-between.
Do you have problems with reading comprehension?
I mentioned 3 (three) tiers of game budgets, SP or GaaS, and tied their average success rate in direct proportion to their size. Where exactly did you saw "all-or-nothing"?
This particular topic was raised on the basis that AA games strategy is to cater to specific group of people (loyal fans/certain whales). And as it's kinda standard strategy - it's imply that it's a working strategy for them, and personally I see nothing wrong for studios go that route. Better this than studio dead.