I don't know your experience level with PC building, so it's always helpful to point these out...
 
Couple of things to check:
It's probably not a cause of this issue, but always nice to check on a new build & confirm, is XMP enabled on your RAM?  Several review sites/youtube channels have noticed that XMP being disabled (and your RAM thereby running at 2133MHz JEDEC speeds) can cause a pretty noticable drop in performance compared to what one would expect, and simply enabling XMP & making sure the voltage is set correctly fixes that.
Also make sure, if you have only 2 sticks of RAM, that they're properly installed in the Dual-Channel configuration (meaning the sticks should not be in 2 slots right next to eachother, see your motherboard manual to know which slots are considered the primary ones).  If you have 4 sticks, that's not a concern since all DIMMs are populated.
I know it sounds a bit odd, but have you tried an older driver, like one released slightly before the 30-series came out?  The golden rule of PC-stuff applies here, if it ain't broke don't fix it.  The 2070 Super isn't exactly "new" and it's possible something in the 30-series release drivers "broke" something for older gen cards, that they will fix later when they realize they broke it.  Not likely, but it's possible.
 
Does this GPU load issue happen in all titles or just the ones you mentioned?  Can you run 3DMark or Superposition or some other synthetic benchmark and see if those load your GPU fully (they should, if they don't something very odd is going on).

I ordered a 2070 Super myself to use as a step-up to the 3080, won't be here for about 10 days though thanks to Amazon's slow shipping due to the pandemic.  I'll see if I have similar issues when it gets here though.
I know the feels with the crap internet, I made sure I had hard-backups of all my games before a recent Windows fresh install cuz I wasn't about to spend several weeks redownloading almost 3TB worth of games lol
Also, does the issue also occur at other resolutions (although if it doesn't that would be even weirder because 4K should load the GPU the most out of any resolution)?

Did you try the second BIOS on your FTW3 ?
 
Are you using 2 separate 8-pin cables from PSU to the GPU ?
 
Which Nvidia driver(s) have you tested ?
 
 
Run GPU-Z   while gaming or running a benchmark software
 
Look at the sensor tab PerfCap Reason & the other monitored info will give you a better idea what is happening
 
 

Very weird that even at 1440p you're not going past 92% GPU usage...
 
I cancelled my Amazon order because Newegg got 2070 Supers in stock (Hybrid, I'm very happy about that) with $50 off coupons, so I'll have an eVGA 2070 Super XC Hybrid here Thursday, I'll report back if I have similar issues then we can compare notes.  I don't have any of the games you mentioned so can't comment on those specifically.
Let us know when you get 3DMark run & see what the GPU load is like on that.