The Mac Pro does not dictate Apple's future. Moreso, the iPhone does. It effects the semiconductor, display, storage and camera industies a lot. Judging by the iPhone 14 Pro hype over a small software UX like "Dynamic Island" I would say Apple 'halo' product is the iPhone. The iPhone made Apple what it is today. We can go on about who saved who. Microsoft also saved Apple but Steve still made fun of them.
Apple is not killing the Mac Pro line it knows its importance. It simply is going the way of what Nvidia is doing in the server space, going its own path. I believe the Pros who need x86, 32bit, Nvidia GPUs/AMD CPUs have already moved during the 6,1 era. The 7,1 is not a leader in 3D nor graphics but some value it for it offers.
Like so, some will value the 8,1 more the 7,1. It all depends on features and reqirements you seek and if a certain machine offers them then users will buy it.