Your old OnePlus could never sustain that speed. It would have throttled in no time. Plus they use to cheat on scores by loading a different cpu speed profile for benchmarks.
The only way to tell if a phone performs well is when you have it in hand and it meets your own criteria.
Benchmarks for phones are becoming less and less important after a certain threshold which I believe we've surpassed in the flagship space.
That's good to hear. I suppose also google's optimisation should play a big role as well.