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It's interesting phase on fediverse, not hard to be well-known right now. I've certainly remember some usernames from seeing them at unrelated communities in different instances and they're aren't even trying to be popular, just leave thoughtful comments a lot.
I know it's not a perfect solution but considering the options, it's better to "sell" my attention to corporate ads in exchange of planting trees than nothing. Even then, I rarely see ads after whitelisting the site.
As far as my research goes, Ecosia seems quite reputable and I support their mission. If they're proven to be otherwise in the future, I won't have a problem to jump ship.