The new Mac Pro doesn't need space for drives, it needs space for SSDs.
The read/write/lifetime considerations for SSDs and spinning storage are still different. For pro machines, one can reasonably assume that writing to storage may be a big deal. Plus, you can put a lot of things into a drive bay besides drives. Plus, you have a drive bay, you can put SSD or spinning media in there (or many other things.) Choice! If you have internal slots for SSDs... well, then that's all you have.
IO is different too compared to when the cheese grater design was invented.
It's different in that there are more options. It's not different in that one doesn't need what one had before. So for a reasonable design, add I/O. By all means. Who's going to argue against more capability? That'd be dumb. But don't be throwing out things that are still widely in use. You know, like.... headphones. Ethernet. HDMI.
it's actually all you need now as long as you are OK with one of those USB-C adapters.
Now, see, there's that again. No, I don't want a bunch of adapters. I don't want extra stuff cluttering everything up. I want the ports. The trashcan is crippled because everything ends up flung on one's desk, power supplies, drives, etc. It's awful. We need to move away from that. And it's not like this stuff is expensive, or like drivers need to be written. Apple should just do it right and quit trying to tell us stupidity = courage.