The onland casino I think has made more gamble addicts. From my point of view, I will be using this part of the world where I am from as a case study. It's true that the online casino is very easier to navigate but one thing you should know is that the online casino is prevalent in nations that are technologically advanced compared to the third world countries. So therefore, in my country, gamblers prefers to go to the casino houses to gamble because they feel that is very easy for them to access and mind you, not all gamblers in my country are conversant or familiar with internet or to talk of using a sophisticated tech phone for gambling. They prefer the where they could meet up with other gamblers to share ideas and enteract with each other before they think of gaming.
Although there are some gamblers who are technologically inclined, they do gamble with their phones but you barely see then doing so because it is all about convenience and self discipline. So they would rather gamble within their confine without anybody noticing that they are gambling and you never can tell if they gamble or not because it doesn't reflect on their personality compared to those who go to the casino or gambling house to gamble.
So therefore, it is possible that the onland gamblers has more addicted gamblers than the online gamblers based on my analysis. This is an open argument and everyone is entitled to his or her own opinion.