I understand that it doesn't fit everyone though.
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.
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 budget usb dac around.
I've pre-ordered the pixel 4A. My phone was dying anyway, but I'm going to like having a headphone jack again.
As for myself, I bought Bose QC35's prior to upgrading to my first jackless iPhone so I was never affected by its absence. I almost never use earbuds.
On the point about affordable wireless headphones, many of us have spent a lot of time and money finding a great wired headphone setup. I don't want to go spend another £300 and 20-30 hours of my time finding an equivalent setup, all because some industrial designer wants his design another millimeter thinner.
Lastly bluetooth still sucks, particularly if you change devices a lot. I've yet to see a BT setup that allows me to easily change my headphones between my laptop, my phone and my ps4 in under 2 seconds.
Personally I don’t know anyone who routinely charges their phone anytime other than when in bed. And personally I don’t know anyone who has an issue with all day battery life. I’ve no doubt these are still issues for some people but again, wireless charging pads are cheap.
I agree multi device Bluetooth sucks. But that’s not your only option. My QC35 are great for two-device use cases. In your scenario I’d use a wired connection for one of the three devices and your instant switching criteria is solved.
(I’m assuming you’re fine with one wired connection given that you’re criticising the removal of headphone jacks.)