I've already decided my next phone is not-an-iPhone. I just hope the Android makers don't try to imitate this move by Apple the way they imitate so much else by them.
If I had to guess, I would say that Samsung would be one of the manufacturers to abandon the jack, but I feel like at least LG, HTC, and perhaps a few others would keep it.
LG's latest flagship even had a removable battery (which is pretty unusual for a flagship at this point).
Maybe I'm wrong. I'll check back in 4 years.
I remember when phones had the smaller version, but it was used primarily for headsets.
A little while later, someone released an adapter, and that lessened the annoyance.
But later phones that had 3.5mm (or 2.5mm) in-built were definitely better.