Phone are available with and without headphone jacks. The ones without sell better. The ship has sailed, move on.

Uhhhh no. Most phones lack headphone jacks these days, so of course the ones that still have them would sell "worse". The same can be said about screen sizes, there are no new phones smaller than 5" "because no one buys them". Of course no one buys something that no one sells.

There are myriad models available with headphone jacks. If it's an important feature to you, you have a lot of choice.

The best-selling mid-range phone in the world was the Samsung A51 if I'm not mistaken. I have one and it has a headphone jack. It's only the highest-end phones and tablets that don't have it.

> mid-range phone

I said "phones", without qualification. So while your factoid is interesting, it has little to do with what I wrote.

Bluetooth is the new line-in/out.

No. This software-controlled madness susceptible to interference from microwaves can't possibly be a replacement for just plugging things in. It's literally a Rube Goldberg machine for sending an audio signal between two devices that are a meter apart.