We're listed on ircstats.org (under our old name of Oragono) as having 84 deployments on the public Internet last year: <https://www.ircstats.org/servers/oragono>
From pseudonymous support requests I've received in our IRC channel and on GitHub, I know of more deployments that are either private (requiring authentication to connect) or on the darknet (we have specific support for running as a Tor onion service). So I think that's our niche right now: small communities who want full autonomy in moderation and control of their data. I've taken a lot of inspiration from Darius Kazemi's runyourown.social: <https://runyourown.social/>
As the co-maintainer of Ergo, since I joined the project in 2017 it has never (to the best of my knowledge) received any funding from Andrew Lee or any company affiliated with him.
In terms of ongoing specification and development work, we take direction primarily from the IRCv3 working group, in which we are both participants: <https://ircv3.net/charter>
a. Ergo [1] as the server for a greenfield setup
b. Gamja [2] and Goguma [3] ) as clients
c. Soju [4] as a bouncer for non-Ergo networks
[1] https://github.com/ergochat/ergo [2] https://sr.ht/~emersion/gamja/ [3] https://sr.ht/~emersion/goguma/ [4] https://sr.ht/~emersion/soju/