Though casinos owners are always watchful.
It is a business and they need to take care of their business to make it continuous running. Although we as gamblers knew it that they're all for the win and what they are giving us is only chances of winning yet we're still going back to them and play until we make it or break it.
But it's more convenient to gamble online now and with the provably fair and having game providers made it easier for them to secure that there will be no one who can cheat them.
Of course the owner hire watchers to watch suspicious activities happening inside ths casino and I think it is better Idea because once you are the owner you did not want to fail your business so you will do everything to manage well your business. Gambling online now is needed to secure because we know there is a lot of people who is good in the technology and anytime they can cheat also so they need to have strong protection to their system.