You say that but many specialty subreddits never returned to their pre-protest engagements. Quality has definitely taken a nose dive in these subreddits as those people moved to other platforms like youtube, tiktok, patreon, or just posting on their own sites.

Mods were rightfully upset because they were losing control of their communities when reddit preferred only caring about their upcoming IPO.

I honestly don't think you could remake reddit if you did everything exactly the same starting in 2016. Corporate social media has definitely ruined the individual aspect of social media that is unlikely to return.

No one wants to share on a place with a bunch spammers.

The API changes were put in place for the purpose of breaking, and did break, slmost all external moderation tool software which changed the task of moderating a forum with hundreds of thousands, or millions of users from an impossible Sisyphean task to something that was actually manageable by a dozen or so mods.

The protest came after that so the timeline is not quite correct.