When I was a kid, we use to look forward to the Olympics. It was a big deal. The whole family would gather around the TV to watch the events live regardless of timezone. We use to follow the stories of the atheletes and it was constantly the talk of the town.
Nowadays, it kind of feels like Olympics are just annoying. Propaganda fest for authoritarian regimes. No one cares. Heck, some people don’t even know that the Olympics are even happening.
How did it go so wrong?
In the 21st century, we interact with the rest of the world on a daily basis. You can learn more about any destination online (heck, on Wikipedia alone) than you would from traveling there for a few days to watch some random assortment of sporting activities.
And I think to some extent we're so used to having everything at our fingertips that sometimes actually going to the destination is less rewarding than one would expect--spend a ton of money (vs. going on the internet 'for free'), deal with customs, deal with the occasional crying kid on the plane, maybe forget to bring an item you really needed, maybe get mugged or lose your passport, have issues with your hotel reservation...
Not to mention the opportunity cost. Compare the number of, say, Summer activities one could consider instead of going to the Olympics in 1952 vs 2022. If anything we suffer from too many alternatives today
Plus there's no Cold War to raise the stakes to the point where anything but the gold medal wins utter defeat.
And frankly I'd wager most people aren't that into nationalism anymore, except maybe the alt-right and its equivalents elsewhere. "I'm just trying to get through the week" trumps all else for most people.