At the time (2018-ish), it was really impressive for on-device voice synthesis (with a quality approaching the Google and Azure cloud-based voice synthesis options) and open source, so a lot of people in the FOSS community were hoping it could be used for a privacy-respecting home assistant, Linux speech synthesis that doesn't suck, etc.
After Mozilla abandoned the project, Coqui continued development and had some really impressive one-shot voice cloning, but pivoted to marketing speech synthesis for game developers. They were probably having trouble monetizing it, and it doesn't surprise me that they shut down.
An equivalent project that's still in active development and doing really well is Piper TTS (https://github.com/rhasspy/piper).
their founders were working at Mozilla when Mozilla sunset its speech products. They founded coqui and released text-to-speech models based on their previous work. They tried to do a mix of open-source and closed-source stuff and introduced weird licensing concept that I never understood. there are many mediocre to good open-source TTS alternatives. they might have struggled to differentiate.
it's sad that people complain about big tech dominance, yet don't pay startups. i dont know the founders but i suspect they will join a big tech company as most of the Mozilla team did and we'll keep feeding Amazon, Google and Microsoft.
https://news.ycombinator.com/item?id=29786132 -- Show HN: Clone your voice and speak a foreign language (January 3, 2022 — 513 points, 112 comments)
https://news.ycombinator.com/item?id=31728939 -- Show HN: Voice Clones for Creators (June 13, 2022 — 71 points, 63 comments)
clicking on the domain name next to any submission shows their other ones https://news.ycombinator.com/from?site=coqui.ai