From the way you asked that question, it's like physical casinos are now doomed because of the growth of online casinos.

How can land-based casinos manage to hold their ground? In the first place, such a question isn't appropriate to ask since land-based casinos are continuously growing and becoming bigger. Just look at how big and active those physical casinos are at those popular gambling havens around the world.

Either online or offline gambling, as long as its gambling, expect it to become more big!