@0x3F Yeah the Zot protocol looks interesting, I'll have to have a more in depth read about it.
As far as DID being unable to change providers, I didn't think it really had any concept of a 'provider'. One of the principles of the spec is 'self sovereignty' which I think is intended to be achieved via a distributed ledger of some kind and cryptographic proofs of identity. I also need to do more reading about this though so I could be wrong ...
One example of a decentralised method using Ethereum is this https://github.com/WebOfTrustInfo/rebooting-the-web-of-trust-spring2018/blob/master/topics-and-advance-readings/DID-Method-erc725.md
Again, I could be wildly off base with this stuff because it's based on a cursory reading of the spec. Pretty exciting though I think!