You say "degrowthers who literally want people to just live with less" like it's a bad thing
And most of these things have impact much bigger than just the climate. They pollute in a lot more ways than that. Resource extraction, manufacturing pollution, transport, waste disposal.
It's stuff like forcing repairability that allows us to do with much less impact on the environment.
In a perfect world, perhaps. In the real world, it very often does.
It really does. You can live without clothes, that's less. You can live on 1500 kcals a day. You would be at the brink of starving all the time but you would be alive. I could lock you in a cage and just give you the bear minimum of bread and water. Just enough heat so you don't freeze and never let you out. That's certainly less. Just how much less do you want?
PS Young people almost always use more resources than the old. When my kid isn't here, our trash and recycling containers are pretty empty. When he is here, they overflow. And he is only a 50% increase in the house's population.
That I think it's an idiotic position is beside the point. Things and prosperity generally are not the problem, and can grow pretty much indefinitely for the foreseeable future if it's done in a reasonable and sustainable way.
There are a lot of things that would work fine if done in a reasonable and safe way but we have plenty of examples of people making unreasonable and unsafe decisions.
Living without AC in a warm summer is one example. It feels like a first world inconvenience to the Green types, that we should all learn to accept. Good luck with democratically convincing everyone else - you'd need authoritarian for a true success in keeping everyone "living with less."