I agree that the exclusivity is a bummer, but on the other hand multiple games exist today that would not without Epic's funding. I just don't buy games on the Epic store (everything I own on there was from a free giveaway). When they come to Steam, I get to buy them on my platform of choice, and the injection of capital means they're much further along than they would be otherwise, if they would even exist without the funding. I just think of it as an Early Access period.

Yes, from an objective standpoint I would of course prefer an open cross-platform standard, but while it's the sort of thing I could see Steam adopting and even contributing to, Epic definitely wants the lock-in. And while Epic would obviously love to be a monopoly, as long as they have less market share than Steam, they're an anti-monopolistic force as a direct competitor to Steam.

In this scenario, boycotting games that include the EOS SDK is a pointless gesture and the only reason to do so is if you're worried about the telemetry in the SDK, which from the documentation and from Satisfactory dedicated server logs is pretty minimal unless you log into Epic through the game. It sounds like your main issue is the exclusivity, which has nothing to do with the SDK, and would be effectively "voted against with your wallet" by just not spending money on the Epic store. But as long as Epic keeps offering significant chunks of cash for timed exclusivity, it will remain an extremely attractive deal for any game without significant pre-relrase hype.