Yes we shouldn't have to, yes it's a step backwards, yes it's not as good, but I suspect it would save you a lot of problems.
Don't let perfect (a phone company making a phone with a standard cabled audio interface) be the enemy of good (a solution for your problem).
It now becomes either something I have to carry around with me always; or buy one for each 3.5mm headset I've stashed.
Add the poor reliability and performance, and we come back to your point:
"Yes we shouldn't have to, yes it's a step backwards, yes it's not as good"
Exactly. So I will absolutely do whatever I can to make my life easier - but I also refuse to pretend this does not make my life needlessly harder - once again, for no obvious gain for those who defend the decision.
Phone jack is inherently different than all the Firewire/Zip drive items. There are literally thousands of technologies, interfaces and standards that live and die like fireflies. But the phone jack is a century old and still works perfectly well, and we have replaced it WITH the technology of the day - who thinks their $300 Bluetooth Bose will work 20 years from now? Or seemlessly plug in to each device they use?
"I've now spent several hundred dollars on the best-reviewed, bluetooth headset for my conference calls, and it's nowhere near as good, or convenient, as my $29.99 wired headsets"
You could buy 50 3.5mm+lightning dongles for several hundred dollars, and stick them on the end of each headset, which sounds more convenient than messing around with bluetooth.
I was thinking of the terrible headsets that some collegues use -- they have USB-A plugs on the end, for laptops. Not sure what they do if they want to join a call from their phone (say out walking). My 3.5mm tip+ring+ring+sheild headphones works on laptops and phones, seems far superior to their single-use devices. But western economy is built around selling you something new every 2-4 years, so needs obsoleting.
But that is patently untrue.
1. I used to have a bunch of cheap, working headsets everywhere - laptop backpack, car, office, home. That whole use case and convenience is GONE.
2. If I was somewhere and needed to take a concall, I could just borrow anybody's headset. No longer the case.
3. Instead of having a good pair of headphones for 2 decades, I now have to buy new bluetooth headphones with unreplaceable battery and aging standards every few years, and worry about charging them etc.
My life has been so much worse since my employer switched to iPhone, that I wrote to my boss, project manager, practice lead, and in the end CFO. And not because "I'm one of those people" - I spend 3-6hrs a day on calls, and life just sucks now. (for those who think Airpods are "fine for calls" - yes. For YOU. Not for other 20 people on the call who have to hear everything happening in 5 miles radius of you. And heaven help us if multiple Airpods join the call!)
So even if we say life got worse for - whatever: 10%, 5%, 1% of population - how has it gotten BETTER for you guys that don't happen to have a need for a jack? The phone is not smaller, it doesn't have a better battery life, etc.
I just don't see the argument here other than "I don't need it, so nobody should have it".
I've now spent several hundred dollars on the best-reviewed, bluetooth headset for my conference calls, and it's nowhere near as good, or convenient, as my $29.99 wired headsets.