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.
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.
