I have a 120Hz TV at home and I watch a lot of football, so I can say it's worth it, but there's one detail nobody's mentioning: not every broadcast takes advantage of it. Most of the soap operas and games we watch come in 60Hz, so the TV's basically "sleeping" in those cases. Now, when you get a broadcast that actually uses the 120Hz (some streaming platforms already have them), or when the TV does decent upscaling of that normal content, then the smoothness really becomes noticeable in the ball's quick movements.
What I haven't seen anyone talk about: the price tag for this difference is pretty steep. If it's way more expensive than a good 60Hz model, maybe it's not worth it depending on how much time you spend watching football in high quality. But if you're thinking of upgrading your TV anyway and the budget allows, a 120Hz panel with good image processing quality (well-calibrated motion smoothing) really does make a difference for sports. Soap operas barely matter, but hey, that's a bonus 😊
Screen size matters quite a bit like people mentioned before - on a 32 or 40 inch you might notice the difference less than on a 55 and up. And heads up, watch out for inflated refresh rates: there are TVs that claim 120Hz but it's just firmware motion interpolation, not the actual refresh rate of the image coming in.