Unfortunately it's illegal under GDPR to run a web service without telling users how their data is used and getting them to confirm they understand. We hate it too, but we have no choice. In future as Matrix becomes more P2P (like Ricochet) then this will go away, unless you choose to store your data on someone else's server.

Most people are happy that we actually spent the time & effort to explain what happens to their data in Matrix (especially given it's unusual relative to a centralised service), and to do so in non-legalese. https://github.com/vector-im/policies/blob/master/docs/matri... is the doc in question fwiw.