If world of warcraft hadn't added any content in 15 years it wouldn't be making much money.

> why would rockstar spend billions developing gta 5 if it was public domain after 10 years?

Because that's still a ton of money. Also every time they update the game with more content, that's something you can only get if you buy or wait even longer. And it's easy for them to require payment to use GTA Online.

> it’s still the cash machine that runs the business today and it’s 8 years old

I don't think it would be a tragedy if they had to put out a new game at some point in the next few years to keep making as much money.

Also the game was already completely free for a week in 2020.

WoW and GTA5 both made back their costs shortly after launch. The fact that there is more profit to be made afterwards isn't an argument for or against longer copyright terms. The point of copyright is not to enable the author or publisher to capture 100% of the profit - otherwise, we'd just issue perpetual copyright title and call it a day. The point is to encourage the production of new works by giving people who create them a "bite at the apple", so to speak. So the length of copyright title needs to be calibrated to allow creators the chance to make a profit, but to not gate further creativity or re-use behind a paywall.

This is, of course, very poorly bargained-for in present law.