Well, for example, upgrading between releases is done by manually editing sources.list and some other steps, and there’s no easy tool for that. This is not difficult, exactly, but for people with little experience it’s a bit daunting. Debian in general isn’t the most new user friendly distro, in my experience. Distros like Mint and Ubuntu make the Debian experience slightly easier. Not that Debian is some esoteric system.

Well, what about just using Debian? It’s a bit hassle, maybe, but if you have prior Linux experience, you’ll be fine.

I’d say it didn’t fail. It was never really a consumer phone. It was an attempt to get hardware in the hands of developers, and it achieved that.

Other posts here discuss why it didn’t receive wider adoption.

I daily drove my PinePhone until I could no longer receive MMS messages, since my service provider has a different APN for the internet and MMS. That, and the modem became more unreliable over time. I like my PinePhone, but an average user would never adopt it as it is.