You can run your own instance or join an instance that tolerates that speech, and federate with other instances that tolerate it. So, the "platform" is not supressing you one bit. Go forth, and be an asshole if you wish.

However, administrators and users on other instances also have the freedom to participate without being forced to listen to assholes ad nauseum. "Free Speech" does not mean "Free (from the consequences of your) Speech" or that other people should be forced to listen to you.

The EU definition of free speech online includes platforms. https://slate.com/technology/2022/10/digital-services-act-european-union-content-moderation.html

Platforms meaning major internet giants.

The reason why Lemmy encourages free speech better than the major platforms is that people can just start their own Lemmy.

The argument that people gave for supporting suppression of political speech on platforms was that "you can just start your own site, you don't have to use twitter/fb/etc". With the death of reddit, we can clearly see that is much easier said than done, but I think Lemmy is making progress in that direction.