Psyklax
Embrace. The big corporate giant dips its toe into an existing project.
Extend. The corp adds features to their app, improving on the community's apps features. Somewhere along the line, a previously open source project will become proprietary and closed. People begin to prefer the proprietary option for the added features.
Extinguish. The proprietary app cuts out the original community (defederation) when a critical mass of users is reached. People use the proprietary app instead of the open and free app, because of the features, but also because many of the people they want to follow are now segmented from them. The original open system dies out from lack of use.
Enshittification follows.
I've just switched from Messagease. I loaded up the layout and I'm already up to speed. Some behaviors are different though, like typing numbers with long press and accessing symbols on the letter keyboard.
Been using messagease for 5 years, and it took just a couple weeks to start typing eyes-free.
My problem with linux phones was the hardware. Either far too expensive or too cheap and slow. And the cellular radio is ABSOLUTELY PROPRIETARY.
I would get one at a $300 price point with 12 hour battery life that can play HD video without hiccups. Also would be nice to have open source baseband drivers in it.
I've got really low standards that haven't been met.
I think if you read the github description, you'll find that conflicts with the philosophy. Would be a nice option, though