But do we have a responsibility to not hinder someone else's free speech? Not with regards to the current post but just thinking in lines with what you said.
But anyway, there are no social media monopolies. We have Twitter, Facebook, YouTube, Instagram, WhatsApp, iMessage, Discord, Signal, etc, etc, and it goes on and on. They’re also very segmented, Facebook is huge but it’s almost irrelevant to kids and young adults. New services pop up regularly because barriers to entry are incredibly low and segmentation is so high.