Hard to tell imo. Big tech has a lot of big advantages and disadvantages over us.

Being centralized and heavily funded, it's a lot easier for them to rapidly create/change new things, for better or for worse. It also means they do a lot of the testing for us. Mastodon/Lemmy formats are figured out from what we liked from proprietary platforms, then we kept the core that made it good. We also don't need to make a worse user experience by worrying about monetization.

We also have a lot less development, and I won't even pretend that Mastodon or Lemmy are anywhere near well developed as Reddit/Twitter backends and other software. We simply don't have the attention and funding to be anywhere near that level.

I don't think we'll ever replace big tech, but I just hope we stay on a healthy trajectory where we are alongside them in popularity.