The nice thing about Game Pass is that after a game has been on the service for a number of months, you get a 20% discount if you choose to buy it. It's useful for instances where a game you want to keep playing is about to leave the service, or you want to get off the subscription plan.
look at this way: a business makes a change (in this case buying vs subscription). do they do it in their own interest or yours?
super simple stuff.
steam presented a bit of an issue about owning what you pay for. because, if their service is down, you can't access your "assets". some people called it a type of subscription model.
with this shift in the industry, outright paying a subscription for temporary access, we move even further away from owning what we pay for.
imagine never buying a house but always renting. why be against it? who is that business model good for? what kind of world are we voting for when we buy into these types of businesses?
in the long term, a subscription model puts us, the customers, at a loss. and a successful business plans for long term.