We all know that there is a virus outbreak named COVID-19 and it's spreading quickly throughout the entire globe. Though preventive and and can be somehow cured and be reduced by healing the specific symptoms one-by-one (based on Is there a cure for the new coronavirus? by Stephanie Pappas), there are still numerous cases in which would affect soon every single person on the planet.
So you're saying that every single person in the world will be affected with this virus?? How sure you are that all of the 7 Billion+ people will be affected? COVID-19 can be a pandemic in the future base on how fast it is spreading right now but to affect every person is a bit exaggerating for me. The largest pandemic happened in the whole world is the infamous "Black Death" which affected only 75-200 MILLION people. can be passed in a lot of different ways, more likely to be through physical contact. And it is obvious that most gambling (especially physical casinos) were bombarded with strangers that aren't that assured if do have the disease or not, and has a high chance where many physical contact occurs (like passing of bank notes and bets).
The main way the virus is being transmitted to other people is thru droplets. Passing of bank notes and other things that came from the host person can be a transmitter of virus. In offline gambling (casinos), a single person who has a COVID-19 can spread the virus throughout the whole place and can affect many people. But then think of it. Casino is a common and usual place where people do often make contact not only by oral communication but also with touching bank notes, casino coins, and even dices and other things used in betting. Therefore, there is a huge chance that COVID-19 would drastically decrease the physical gambling and do somehow can change gamblers' physical gambling onto digital one. And with that, it can somehow increase the community of overall cryptocurrency.
With what is happening right now, the revenue of the casino's can go down drastically because gamblers will not go to a casino and risk their life there especially if their country already has cases of the said virus but on the other side online gambling sites can increase their revenue too because gamblers who can't control themselves will just try to gamble online. It can increase the community yes if they choose to gamble using crypto. There are some sites who are accepting fiat currencies too 
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