Looks like PostmarketOS (mainline Linux for phones, with choice of frontend, such as Plasma Mobile or Phosh) has demoted all their previous "Main"-tier devices to "Community" or lower tier:

https://wiki.postmarketos.org/wiki/Devices#Main

Anyone know whether this is a sign of a push for being daily driver quality? Or a sign that volunteers previously doing promising work have drifted away, and they're acknowledging that?

I am the pmOS maintainer for the PinePhone. It was demoted from main to community because I was the only maintainer and one of the criteria for main is to have two or more maintainers. ( https://gitlab.postmarketos.org/postmarketOS/pmaports/-/merg... ) Originally many pmOS core devs were maintainers, which is why it was in main, but they all lost interest and it was about to be demoted to testing / unmaintained, so I volunteered to become the maintainer to stop that from happening.

A blanket statement of a phone being "of daily driver quality or not" is impossible to make because everyone has different expectations of a "daily driver". I have been daily-driving the PinePhone since 2021 (it is my first and only smartphone) but that doesn't mean everyone else will be happy with it.

Main is described as "The most supported devices, with all the features and stability you'd expect from a regular OS."

Unfortunately there was/is no device supported by postmarketOS that fits that description. You'll need at least good telephony support including 4G features like VoLTE, proper camera support (not potato polaroid from the 80s quality), Wifi, Bluetooth, geolocation, working GPU acceleration, media hardware decoders, decent battery life. And I'm probably forgetting a few things.

Let's hope that initiatives like https://liberux.net/ will help make a fully working, long lasting device available!

Unfortunately, and as much as I like Linux for phones, I think it's very, very far from AOSP. It completely misses the AOSP security model and the apps (no, I don't believe that running waydroid on Linux is entirely viable, otherwise instead of Linux for phone we would have Waydroid as an alternative to Android).

I think the only realistic alternative would be to build upon AOSP properly, with Google being just a contributor instead of the owner. But it cannot come from a community fork by someone in their garage, it has to come from Android manufacturers. I was hoping that Huawei would start something like that, instead they went with their own HarmonyOS.