Digital Foundry knows fuck all about performance expectations on a game and engine they don't know.
Current open world games are struggling to go over 30FPS on consoles because Unreal Engine has a problem with shader compilation and most games aren't making proper use of the fixed function I/O acceleration blocks in the consoles.
The PC doesn't have these I/O blocks and DirectStorage is still strangely absent from most AAA games, which is why DF thinks devs need a 5GHz Zen4 to run some games at 60FPS.
The thing is, most devs aren't Rockstar North, who depend on one ultra-successful franchise releasing one title per decade.
Rockstar North can't afford to not optimize the next GTA to its last bit, and they're 100% going to optimize that title to the I/O Complex and Velocity Engine. They're going to make sure that the render portion is the bottleneck in that game, and the rest is properly optimized to run in 7x Zen2 cores at >3.2GHz.