Considering how much of the Internet is now backed by AWS... yeah good luck with a full, 100% boycott, unless you're willing to install a plug-in to let you know which parts of the web are on AWS and specifically avoid them.
That being said, a 100% boycott is borderline puritanical. It's very easy to order nothing from Amazon, and if enough of us do it will make a noticeable dent in their profits.
It's a real pain in the ass for the best source of news about the games I play to either be reddit or Discord, so my options are shit or shit. Sometimes developers post clarifications on game mechanics on the subreddit, and that's the only source of that information. I wish more companies could understand the benefits of instance ownership, especially considering all of the ongoing issues with social media owners. It'd be great if that kinda news would migrate somewhere better so I could finally ditch reddit permanently, but I'm sure I'll just eat a ban eventually.