All this talk of "stupidly expensive" and "value not there" doesn't compute when you're talking about a purchase by someone with the means to make it happen. You may think it's stupid, you may think the value is not there, but other people think differently.
Why are there so many used ERs for sale? I suspect a lot of those trucks for sale are from the zombie apocalypses buyers. Covid spawned so much anxiety and stress that some folks went out and dropped a ton of money on a get-away vehicle. All the big truck makers, EC, ER, and GEV, worked overtime satisfying demand from 2020 to 2022.
Many of these buyers had zero camping or overlanding experience, but what they had was cash. We have all run into people like this, formerly empty beaches in Baja have been wall-to-wall with them over the last few winters. When the crisis abated and the overlanding dream didn't meet their expectations, the truck went up for sale. I suspect we're at that point now.
There are probably some good deals out there for cash buyers if a big truck is your thing.