There's "what you want" and "what you will pay for." In order for change to come, someone has to be remunerated (either financially or spiritually) for what they do. Reddit needs to make money. It has not done so for lo these many years. In the runup to the next dotcom crash, that's been okay... many many companies have not been required to make back any of their cash because they're "disruptive" and "some sections of the net are ripe for that kind of explosion." But 4chan has never made money, and never will. Amazon barely makes money, and never will. Facebook? Facebook makes phat stax. They will continue to do so for as long as their ad platform works, which they're kind of fucking up right now. But at least they have somewhere to start. Reddit has the ability to target individual customers yet self-serve remains the biggest clusterfuck in the history of advertising. Anyone with half a clue starts to look at "the most hateful site on the Internet", contemplates the fact that it will never make money, and decides that their money is better invested elsewhere.
They've been fucking up their platform. The feed is kind of a gerrymandered nightmare and it's caused ROI on ads to plummet. They're still the best bang-for-buck for local advertising, but not nearly by the percentage they used to be. They're also really polluting everyone's feed with clickbait bullshit and they make it really tough to see the posts you care about, which drives down visibility. I know I didn't install FB in my new phone, and I got it in November. People have a lot of Facebook fatigue.