Great, staple a few ML accelerators to your NIC. Nvidia sells them! You could build an entire supercomputer style setup 100% optimized for Twitter data movement and computation with COTS hardware IMO.

I strongly doubt that entire datacenters need to be used if and only if Twitter obsessively optimized for hardware usage efficiency over everything else. In reality they don't and make some pretty big compromises to actually get stuff built. Hardware is cheap, people are not.