If GTA6 shows up for free in a web browser day one, it will for sure hurt sales. Not sure how anyone could argue otherwise: people are paying to play GTA, not paying to support Rockstar. These older games though, I agree with you.

I don't think that's true. I'm contemplating buying a Switch 2 just to play the new Zelda remake. But I might also now just play an upscaled emulation of the old game or even perhaps a recomp of the remake if it gets made fast.

Aka lost sales.

Relying on support / the kindness of strangers is quick way to financial ruin. It's about providing a service / product that has value that consumers will, if forced to, pay for.