There is a reason why Quantum Break ran so poorly on PC, and that is because its engine was initially programmed to be highly optimized for the Xbox One hardware, and then the PC, in turn, had to run it in a very inefficient way.
Quantum Break runs poorly on PCs?
You probably refer to benchmarks in Ultra setting or above in native resolution without the "temporal reconstruction" performance cheats.
If you choose similar settings to the Xbox One version or the Xbox One X version, the PC version delivers similar or even better performance.
My first playthrough was the 30fps-locked Xbox version. After playing it through again on PC I can't go back to the 30 fps.