This can usually be improved by turning off all the crap you want anyways (noise reduction - smart dynamic contrast adjustment - anything similar). Opting out of the ad tracking and personalisation also seemed to slightly speed up some TVs as well for me.

Also experienced a Samsung TV at an Airbnb once that was insanely slow - turns out it had very little storage space to begin with and was literally at 0 remaining. Deleted a few larger apps and reinstalled the remaining and it sped up a lot once it had some cache to work with.