Somewhat agree. IPFS makes sense to use as a caching layer and certainly it could help reduce operational costs of a Mastodon instance, but it's too slow to be the main server and it is impractical for mobile clients.
What I'd like to see is the possibility to send multiple URIs when storing/sending information about attachments. This one leave to the client to figure out whether to use a HTTP link or IPFS, or magnet links, or embedded data...