It still has tiny market reach.

You are moving the goalposts, you said:

The lack of polish is a function of the inability to use the hardware. The hardware is tightly gatekept so competition _cannot_ exist. [...] Once we can actually target the hardware, open source alternatives will be much better than first party options.

So, it's not the hardware gatekeeping that is the issue, it's that nobody is polishing the experience for hardware that already exists and qualifies. The hardware can also be purchased very easily in some regions (e.g. Europe). I can literally hop on a bike right now and pick up a Fairphone in ten minutes. I know that it's different in e.g. the US, but Murena has been selling them in the US for years now.