Online gambling has many flaws. For example, the gambler does not need to go to the casino. Gambling is available to him 24/7. Many gamblers are just too lazy to go to the casino if it is located far away. Online gambling is even in your phone.
What you think of as a flaw is an advantage to many people, and what better example than what happened during the pandemic, almost all over the world casinos were closed down and you did not really had the option to gamble at a physical casino anymore, so people decided to switch to online gambling as a way to satisfy their desire to gamble, and now many people are finding out they prefer to gamble online as it is way more practical and cheaper as well.