Subreddits doing this will have a much bigger impact than end users, because large masses of people will never do anything inconvenient on their own. This is the reason why capitalism doesn’t self-regulate for better environmental standards, for an example. The whole personal carbon footprint thing was invented by an oil company to shame individuals so we can blame eachother for our consumption instead of regulating energy companies. Nothing changes if we rely on everyone to do the right thing without any external motivations (be it environmental regulations or closing subreddits).

That’s not to say you shouldn’t also look at your own actions - personally I deleted Apollo on my phone and blocked the reddit domains on my work laptop and home network. But big players (I.e big subreddits) need to be part of the change.