It has so many Thunderbolt ports because it doesn’t have a GPU, so 8 PCI-express lines can be allocated to 2 thunderbolt bridges.
Mac Mini will only shine when it will transit to Apple Silicon.
I think it shines anyway tbh, but probably not as a desktop replacement with
out a eGPU which is I guess where it gets measured the most, and found a little lacking. I've a couple of the 6 core i7 units and they get a bit laggy even on 4k screens. Can't imagine being sat in front of them all day using them like that, it would be painful - but that's not how I use them. They're effectively server machines so I tend to screen share to them or RDP to the servers/OS units they're hosting. They're epic at that.
TB3 port for a dedicated 10Gbe connection to my iMac Pro means fantastic networking. Samsung X5 on them for brilliantly fast storage, a 10Gbe TB3 connector on one of them because
somebody forgot to order the 10Gbe upgrade when I, ahem, they ordered the second one etc.
I would consider one as a desktop machine but I would definitely include an eGPU in that decision.