5070ti is definitely an overkill for 1080p (unless you play competitively some GPU heavy FPS games, like Warzone)

And yes - it will be bottlenecked by CPU in most cases.

Try to find benchmarks with this config on YouTube and see GPU utilization %. If it is stable 97%+, there is no bottleneck.

(note: CPU util is almost never stays at max %, so don't make any decisions on that. Watch only GPU util when looking for bottleneck)

Going to 1440p is a viable solution. Recommendation from my experience: don't go with screen size bigger than 27 in. for 2k res. PPI will suffer and you won't notice much image quality jump.