There are responsibilities that social media platforms have when it comes to the unfettered amplification of things that are known to be false. Those can often be very dangerous and have violent consequences, or other consequences that might be political consequences but are related to believing in things that are verifiably not true. Much of politics operates in a grey area where some things that are said are true and some things are not, so it can be dangerous for social media platforms to regulate with too heavy of a hand and stifle speech.
When it comes to de-amplifying statements that are known to be verifiably false, social media platforms have an obligation, in my view, to not try to share that information widely with their users.