Getting rid of his cap numbers for the next 2 seasons alone is worth the trade. The compensation might be a bit lower than what people wanted, but I'm guessing that this is his value based on his contract.
We're probably not winning shit in 2022, so why keep him for another season or 2, and then cut him or dump him for a much worse draft pick? This was a good move. I know he's a great player, and he's fun to watch, but it makes sense to get rid of him.
Get your angst out now, and then get the fuck over it. There is probably more to come.