I think a very small percentage of users would justify a purchase on repair-ability & sustainability alone (privacy is not it!), if it does not save them at least a little money in the long run and as things are it does not. If it was just a bit cheaper they could sell 10x as many units & normal people like me would be happy. I think this is reasonable to ask for, yes the phone is more expensive to make, but software support is not nearly as expensive as you think. Android is very easy to update and port these days, sure it’s like 4 engineer salaries to keep some degree of testing running alongside development, but if they sold more devices, then the relative cost would go way down.
Then again, if they can maintain profitability by targeting that niche market it’s good for them, I just wish someone took ‘right to repair’ & ‘right to own’ to the masses.