true obviously EAS is EOL, not death.
But I see more future and open standards/ease of use in jmap than in EAS.
I imagine that cloudron could build a webmail and calendar front end with jmap proxy with the compatibility to all current calendar and contact apps on the store because jmap can just be a proxy it doesn't need to be integrated into the mail server.
Apache James complete mail stack use it as a proxy is not integrated directly into the mail server, it acts as a gateway from the internal network that speaks in IMAP and external that use rest API.

Jmap is just been a standard for 2 years or so, and it's used by big providers for their proprietary webmail, and it's easy to develop UI on top of it, because it's just rest API.
there is a really good comment on rainloop issue for supporting jmap