Maybe not the most effective but Helldivers rolled back the requirement to link a Playstation account (on PC) after massive outrage and pushback.

Boycotts are one thing, people simply not buying because a company's reputation is ruined is another. What I think we really need is simply to spread the word about how sony is a shitty company, let people know the stuff they buy from them gets deleted. That's enough to really smash up sony's revenue. Tech people naturally assume other people are highly informed about tech stuff, but they aren't, they're watching tiktok ai sexy cat videos and assume the reason grandma lost her copy to Alien: Resurrection was because grandma isn't very good at computers, not that sony deleted it. Indeed, I think, because sony is concurrently removing physical media the outrage probably will effect their bottom line in some ways when the next playstation comes out.

Look at how the firestone tire scandal in 2000 effected their company's bottom line. Or how the click of death effected the fortunes of the owners of Iomega. Reputation actually does matter sometimes.