People should try calculating the actual value of the games they have played (and at least mostly finished or be honest if you wouldn't actually have bought it if you couldn't try it for free) on Game Pass and see if they actually saved money over the subscription or not.
I did and I would've paid out £750 for 5 years of Game Pass (At UK base price, I'm on PC so need Ultimate for the best titles) instead of the ~£850 I spent on ~35 games in that time and I wouldn't own any of the games. That £100 extra is well worth it to me to have constant access to titles so I can replay them down the line.
I even used the RRP when I usually get games 10-25% cheaper than that via cdkeys so its not even a fair comparison in my case.
edit -
Wizz-Art
points out below that the loophole was 3 years max. So I've updated the figures here.
I understand a lot of people used the "Gold upgrade deal" loophole and got 3 years for £50 a year. So those people have gotten 3 years of Game Pass for £150. Then £300 for the following 4th and 5th years, giving a total of £450 for 5 years. Obviously that is a big saving over what I spent.
Think about this though, I can choose to buy or not buy games that I want (over the next 5 years) as they come out, or even wait for them to drop in price and buy them heavily discounted. You've given MS ~£150 up front and will spend another £300 for the 4th and 5th years together. I'm guessing most people will end up buying at least some games through the service down the line because they aren't part of the subscription.
These games are marked up by 10-25% over other online stores so you aren't making a saving at all and its locked to the terrible Windows Store if you are on PC. Do that 10x (in 5 years, so 2 games a year) and you've spent MORE money than I have but you own 10 games instead of ~35. So its fine if you don't intend to buy any AAA/full-price games outside of whats on Game Pass, but lets me honest there will be AT LEAST one game a year thats not on it that most people want, like Cyberpunk 2077, or the latest AC/Far Cry as examples.
The majority of the extra games I own will be the smaller indie games that I paid ~£15 each for (~£350). I'm much more likely to actually replay those games since they are shorter as well so I really do want to own them more so than the AAA titles.