I have my go-to games that I periodically return to for short gaming sessions or speedrunning, like GTA V, Witcher 3, all Half-Life games, etc. So those games have always to be installed without the option to uninstall them. Add 1-2 current AAA games to that I’m playing simultaneously plus couple of more recent emulated games like BotW or TotK, and your 512GB drive is pretty much full. In my case, 1TB may be sufficient. But if I go through the trouble of upgrading my storage anyway, why not put a 2TB drive inside, just to be sure.