Game Pass was never a sustainable business model. People liked it because when a new game came out, they could buy a month of game pass for like $15, play through the game in a couple weeks, and cancel. It was a really good deal because Microsoft has spent the past decade+ trying to recover from their terrible fumble of the Xbox One launch, so they were subsidizing gamers to come back to their platform.
With the money being spent on AAA titles these days, they are not going to make any money without increasing the price of Game Pass majorly. The big price bump they quickly backtracked on was an attempt to make Game Pass somewhere closer to being profitable.