Not all 4K is truly 4K. Depends on how it is shot and if it is upscaled or using actual 4K cameras. 4K Blu-ray or on Directv looks great. 4K on Netflix or Disney+ etc is throttled so it’s not full quality either.
But I watched a few football games this year, the Duke/UNC basketball game, etc and they all looked fantastic. HDR is, in some cases, more noticeable that the fact that it is 4K in and of itself.
(Also, interestingly, for the Duke UNC game there were no commercials… they just had a camera feed from rafters during TV timeouts showing the whole arena and the band/cheerleader routines etc which was kind of interesting)
Most of the Avalanche games are in 4K and I’ve watched some of those too (not an Avs fan, just watching due to quality and liking hockey) but I think their broadcast must be up scaled and not true 4K.
Your TV will also have an impact here. A nice OLED from LG or Sony looks way better than the fake Samsung QLED, a Vizio, Hisense, etc or some other off brand. I’ll never buy a non OLED until some newer technology comes along.