I've flown on a few different aircraft in economy this year, the Virgin 787 and Finnair A350 were absolutely fine, I don't remember the easyJet A319 being too bad but the Wizz Air A320/321 were quite unpleasant. I'm not sure I'd write off airlines the same way I do train operators yet as it only really seems like the low-cost carriers use bad seats which is perhaps as you'd expect!
I think the only way to actually change this trend would be for people to start actually linking long-term injuries to them. As much as I dislike the seating on stock like 700s, 387s, 800s etc, long journeys on them has never done me any harm. 345s on the other hand, doing several long journeys a week has actually left me with lasting pain in the relevant areas that takes a couple of days to subside. This is one of several reasons I try not to use the Elizabeth line for longer journeys now. I find myself wondering what the consequences might be if I did the full hour each way, 5 days a week every week. There must be people that suffer consequences from sitting on an uncushioned surface for 10 hours a week?