You're missing my point and a tonne of other pro user's points.
Will a video card really be 5X faster by next year? Really? I didn't realise that GPUs were advancing at such breakneck speeds. It seems to me like the 1080Ti is still revered, and yet I believe that's over a year old? So it's not like people are complaining there... and that's just the gamers.
LOL at buying a new GPU every year results in me losing my money? How do you figure that when I'd be spending money every year?
You fail to see that my cameras have operated using 100mb/s file footage since 5 years ago. Even with the upgrade to 4K, I still use the same 100mb/s codec.
In a year's time, I'll still be using it.
In two years' time, I'll still be using it.
I'm willing to bet that in 3-4 years' time, I'll still be using it.
Therefore, in light of this, you can see that I will still have the same, super-powerful, perfectly-supported iMac Pro to run FCPX with then as I will once it's delivered.
The only time I'll upgrade my codec is if/when the time comes to move to HDR, but the workflow for HDR is extremely complex and isn't something that's likely to happen within my business or even in my industry any time soon.
This current iMac Pro is also running 8K footage natively, so I have room to grow further down the line as well. The iMac Pro also means that I can take on about 5-10 extra jobs for next year, as my editing speed will be that much faster than it is today.
Therefore, I think I'll be perfectly happy with my purchase, and for people like you, you will be perfectly happy next year as you can save money buying a new GPU every year for your new modular Mac Pro.