2 years, optimistically. 1 year if you want to be a pessimist and realist like me. Current amount of content needs to exist on internet with the users hooked onto big sites. Content is being purged, users are going away.
Some are quitting social media altogether. Others are gathering on fewer websites outside of Big Tech i.e. Fediverse. Some are using few platforms like Telegram and/or Discord. Some simply heavily restrict usage while sticking to big platforms. Many are simply social butterflies that love their Snapchat, Tinder and Instagram for hookups.