Well, we are a bunch of cockroaches, we will adapt. I get that some internet posters could stay in their parent's basement forever without coming up to see the sun, but most people need to socialize. A restaurant is probably more dangerous than a stadium. You have to take off your mask to eat. My guess is masks will also evolve so they are more comfortable (and stylish) to wear. (We are vain cockroaches) Either way, sporting events are not going away forever......too much money is involved.
As for crowdless games, some networks mute the crowd noise so much already it is hard to even notice they are there unless they pan the crowd. Again too much money is involved not to.