Kinda bad example: the server you are posting on (lemmy.world) literally started during the time of the subreddit blackouts, and other servers’ user count shot up 5x, 10x or more. It’s likely the surge would be muted without it, and even if more than half left Lemmy and returned to Reddit, it was still the first time it could even be considered a competitor. Its a positive and concrete resulf that came of it.

I dunno what changing a profile pic can do, without more of a goal than, “get a CEO to look at clippys and think its funny”. It would have a positive effect if it was even something small like telling people to change the profile and donate $1 to EFF.org