Does it make sense to create a new legal category of pure-platform companies, who must allow all legal content and cannot impose their own "community standards" ?

With growing frequency, people are accusing social media companies of political bias, and suspending or banning users for posting political contents they disagree with. The reasons the companies gave for the suspension or ban, if they gave any reason at all, is generally the user has violated their community standards, content policies, or something similar.

In light of this, does it make sense to pass a new law to create a new category of pure-platform media companies ?

These companies must allow all legal contents, and cannot legally censor users using their own standards. Their only obligation regarding content is to make a reasonable effort to remove contents that are likely to be illegal.

They'll also enjoy some new legal protections. They cannot be discriminated against, or have their service negatively affected by their suppliers, based on their pure-platform status, or the content on their platforms.

For example, if they rent cloud service from Microsoft, then Microsoft can't legally cancel their service because the contents on their platform violate Microsoft's own standards.

Of course, being a pure-platform company is 100% voluntary.