"I specced up an equivalent NUC and there wasn’t a lot of difference in price, and the M2 is really fast."
You must be putting a lot of stock in the CPU and 10G Ethernet. Because the pricing on storage and RAM, which are much more important resources in most self-hosting scenarios, differ an extreme amount since you can't upgrade the RAM in the M-chip Minis. They also cap out at 32 GB which isn't bad but half of what say AM4 can do. Power Efficiency is of course also great on the M-series chips which is worth something.
If we're purely talking Intel NUCs then the i7s and i9s do get expensive but so does the M2 pro. M2 is absolutely faster than i5 and i3 but I can't really imagine a use case where that would matter for self-hosting?