For me the best advantage of online gamblers are it is easy to access they could open it anytime anywhere they want they don't need to go to any sports betting place just to bet.
And they could continue to gamble even in this pandemic because they don't need to leave their house.
I think some offline gambling places have started to make gambling places online, even though only a few but I am sure nowadays many prefer to do online gambling because it was proven when this pandemic many cryptocurrencies have increased in price so maybe this is also the influence of the rise of online gamblers.