Those owner of the casino are don't have choice to closed or stop operating because that is from the government.
Unfortunealy they have to close business if the government asks them to. But the thing is that owners and investors need not worry since they are already rich as anything.
Online gambling owner are happy for sure it because most of the player play to their gambling site.
Not exactly. You have to understand that in order to run an online site you need to have land based developers, support teams and other humans involved in it. These people need to work as well. So if there is a lockdown and they can work from home then its good. But this leads to a lot of logistical problem to the team. Still it is possible to run the site like this.
There is a lot of advantages of playing online than old gambling.
That is the wrong way of thinking. There is both advantages and disadvantages. Learn to look at things from both sides of the spectrum.