As you say “It’s almost impossible to have a real debate because people” know the main arguments of the side but intentionally hide them to instead present their own straw men while presenting the side they don’t like as outrageous and simply dismiss their main arguments as distracting side arguments.
If the government wants all speech to be available, it can provide a space for that itself.
Honestly, I really feel like this is right at the core of the problem right now: The government does not do this. There is no "public square" online that's genuinely publicly owned and operated in the public interest.
Corporations are not people. I agree that small independent websites hosted in someone's basement should have the right to pick and choose what they host, but when your service becomes so popular and widely used that it's effectively a standard public communication platform (and is marketed as such), the rules should change.
Calling such entities "people" is at best misleading.