Esports tournaments actually do get cancelled due to real-life events, especially when it comes to major tournaments which are common with games like DOTA 2 and CS:GO. There are also exclusively online tournaments, but they're usually reserved for smaller events and lower-tier matchups and it's generally ideal that higher-tier teams play in person.
On the CS:GO side of things, the anticheat programs employed in third party services outside of Valve's own system are actually extremely sophisticated and manage to filter out almost all cheaters, but there are indeed incidents where external devices are used to cheat and such, but those incidents are generally very isolated.
Recently there is a charity game event in DOTA 2 where there is a big prize pool that will donate to frontliners like doctors, nurses, health workers, police and many more; and also to people who lose their job because of the quarantine. My friends and I planned to bet against each other, I bet in the game of TNC vs Adroit (I'm in favor with TNC) and I lose there because the winner is Adroit but for me it is okay because there is an internal agreements within my friends that whoever losses in the game, will donate another 20% of the money that we bet.