It is sad indeed that the development of clients relies on the volunteer work of a very limited group of individuals, mostly explainable by the lack of "hype" around Jabber/XMPP.

FWIW it's been smooth-sailing for me and my non-tech family and friends for many years now. BTW, OTR is deprecated, and OMEMO just works.

This project looks promising too: https://prose.org/

> Windows, where most people live

Most people live on their smartphone for IM these days, at least in my circles. I have been surprised by how few people are actually interested in getting a chat app on their "real computer".