It is not that easy to have a "decentralized" platform, it is not easy to actually do anything decentralized. People see blockchain and bitcoin and think anything could be decentralized but what they are wrong is that blockchain is perfect for a currency, it was made for a currency, how the hell would a twitter type of social media platform can become decentralized with absolutely no administration or rules?
People would literally write "I would like to hire someone to kill a person" or something illegal and if it is truly decentralized and not have an owner that person won't have any troubles until figured out who they are. That is not something that easy to manage and I feel it would be quite difficult to build it on technology sense but also impossible for the legal sense.
not fully decentralized like that, Twitter will still use their TOS. I also wonder what else Twitter can do while there is already an example from Mastodon's ActivityPub. Decentralization will also confuse Twitter where they are known to be very strict in prohibiting something that is different from their provisions, so what exactly can they provide?