As well as all your points (which I 100% agree with), my other issue with these dongles is simply that they stick out way more. If I buy a pair of headphones with an angled connector, I can plug them in and wrap the wire a little bit and then when the phone’s in my pocket, the wire takes up basically no space and doesn’t get smushed about by my leg.

With a dongle, I need an extra couple inches of vertical space, and because the wire/connectors are sticking directly out the phone, they get bent all over the place. Absolutely crap design. Yes 90 degree USB-C to headphone jacks exist but they take up way more space than just a headphone jack.

Well Jolla phones run Sailfish OS which doesn’t support this anyway so probably not the phone you should be buying (And the phone supporting Sailfish OS doesn’t suggest at all that it’ll be able to run a “regular” Linux distribution either)

I use CalyxOS on mine. It has microG all working by default so if you need that sort of thing it’s probably the easiest way to get it up and running