Earlier quoted context omitted.
If what you want is wired earbuds that connect directly to a jack on the phone, nothing has changed. Such earbuds still ship with iPhones today. If you want to use wired headphones, the $9 adapter works well. Wireless headphones are also widely available and have batteries that last all day. I realise the above doesn’t perfectly cater to all customers, but anecdotally it seems to cater well enough to enough of them.
The main issue for me personally is not being able to charge and listen to audio at the same time. The main use case for headphones on my phone for me is watching streaming video in bed and that drains the battery pretty fast. I know there's a (kind of bulky) dongle for charging + headphones, but I'd rather buy a device that has the ports I need already. The $9 adapter is cool though. Afaik it's pretty much the best…
I've pre-ordered the pixel 4A. My phone was dying anyway, but I'm going to like having a headphone jack again.