I’m don’t understanding the claim of Matrix being decentralised. In the end I host a server and you talk with me. I give you the choice of choosing the authentication. For that I need an account at the authentication provider like Microsoft.

So all authenticate with Microsoft.

I create a user for them at my server which is still be needed to have the at least the timeline saved.

At which point I have decentralisation here?

And because I can’t handle the traffic on my raspberry I host this on a PaaS/SaaS provider like AWS.

That would assume all web servers are decentralised web3 technologies.