This is true, but I also don’t see why it matters. In practice most users who want the highest performance level will choose the Mac Studio form factor, which is far more convenient.
The Pro chassis is an alternative enclosure for use cases that require PCI expansion cards for niche applications.
In the pre Apple Silicon days the highest performance was always exclusive to the Mac Pro.
It’s disappointing that Apple wasn’t able to make something better than an Ultra chip and the RAM limit for the new Mac Pro has decreased and is no different to the studio.
The Pro chassis is an alternative enclosure for use cases that require PCI expansion cards for niche applications.