Moving from a world wide web to a decentralized, fractured web? Instead of WWW you have FBW (FacebookWeb, GW (GoogleWeb), AW (AppleWeb). What a sad future that would be.
If there is no service then GDPR acts as a higher precedent. EU would have to change their law that users are not allowed to store XYZ content on their own harddrives.
So yes, P2P/decentralization is a perfectly legal alternative for the time being.