I'm sorry that Rubicon was crossed a long time ago. When you told businesses who they must serve. Hilariously, many people want it both ways, they want it illegal for a bakery to not make gay wedding cakes, but also want twitter et all to stop people from saying bad things.
I am not a free speech extremist, and recognise you need to balance the competing demands as these platforms are defacto digital town squares. There are several problems that currently exist. They are:
1) Who decides what is and isn't on the platform
Now that the web has effectively been centralised into a handful of organisations, being locked out of a platform can be seriously harmful. There are no appeals, or arbitration on decisions made. No courts to provide an independent check.
2) Asymmetry of rule application
The biggest issue is rules are not applied fairly. Certain types of people seem free to repeatedly break the rules on platforms without recourse.