FWIW wasn't that Mac Pro in the era where the Mac Pro was useful and had bigger CPU/RAM options than other models?

Or did he do it again when the Mac Studio exists?

Yeah, it was the last of the real big Xeon-based ones, which had its reasons to exist.

Still a very pricey machine.

The one who buys the Mac Pros is not the big spender; that would be the one who won't stop talking about his vacation homes and mechanical watch collection.