They honestly don't realize how much of a feature that is. This is literally a kill if missing feature for me. I'm not due for a phone replacement yet, but when my device does end up reaching end of life I'll probably replace it with the successor of the 3a.
I really liked my 6P, but I bought it used and started to find the battery life untenable before I hit the 2 year mark! Then the Pixel sale hit and I got a 64GB for $400.
My only headphone jack use case is my 1970s receiver, where I use an RCA adapter. Plan to test the USB-C adapter but haven't tried it yet. Don't love the idea of two adapters...
I just got the battery replaced on my 6P for around $115 after almost 3 years of extensively using it and it performs like a brand new device now. I also like the Oreo more than Pie OS which my wife uses on her Pixel. So I just want to get through a couple of more years on 6P before I buy a new device. 6P has been the best $500 purchase for me so far.
However, I still want a headphone jack and a smaller phone. I'll be riding out the original Pixel for as long as possible.