large companies who can afford the security infra to do those checks and store that data
There is no such company. This is just another way to ban “harmful” content. Verifying your identity and age to access restricted content is practically guaranteed to result in your identity being compromised within your lifetime.
Elon is not in Brazil, and making the service available via CloudFlare was not an action taken in Brazil. Brazil should be able to seize assets in Brazil and change how they block access to prevent Twitter from doing business in Brazil, but arresting people in other countries for something like this is extreme.