As I said, I'm all for keeping old ports because I have been doing this for decades and have lots of legacy equipment. I expect you likely have a similar backstory.
The problem for you and I is that removing the A ports causes us to have to get replacement cables or dongles if we don't already have them. I see our existing accessories as already sunk costs into the e-waste future.
The problem I have with the "better for the environment" argument is mainly for the truly new users that buy their first new computer and go to add accessories. If it were me, I expect that I would probably just look at the prices and just buy USB-A parts because they are usually cheaper. Fully understandable, but that is just adding to the accumulation of legacy parts that are already starting out closer to their eventual End Of Life, and extending this grandfathering cycle ever farther.
But as you said, I'm simply playing devil's advocate, mainly because the notion of being environmentally friendly while upgrading computers strikes me as at a bare minimum quite contradictory. I use my phones and computers long past most, and usually keep them as backups even when I upgrade, but I still figure my e-waste footprint will be rather large when they eventually carry my cold corpse out.
Edit: I forgot to respond to your theory that USB-A is longer lasting. I haven't yet noticed that, having had low quality and high quality cables for each. I have used A longer though, so perhaps I will find more failures with C in the next 20 years. At least a couple of the SS10 USB-C cables I've purchased have had very high quality connectors, as they've held up well... I quite miss MagSafe on the MacBook Air M1, but at least those USB-C ports and these cables seem to be able to handle the occasional accidental pull, even at an angle. I do prefer the reversability of C, though, but I find A easier to actually push in if I actually have the initial alignment correct. I would say they both have many good qualities, and they sure beat RS-232!