I think it's a given that gambling online makes one more addicted. You have it in your computer, on your laptop and even on your phone anywhere you go.
I guess, yes online gambling can be more addictive as compared to real gambling. When you do physical gambling, you may face some hurdles like going to the casino and how long you stay there etc etc. With online gambling you can just stay online and gamble the whole day and night with no one watching or stopping you. This is like the same addiction like some teenagers get addicted to watch porn all night because its again easily assessible everytime & everywhere
A gambler can be addicted to both physical and online gambling platforms. But why the chances of being addicted online are more has been mentioned in your words. If a gambler is gambled to physical casinos, he needs hard money. He can lose as much money as he has at that time but he has to stop as soon as the money runs out. But on the online platform, a gambler can continue his gambling without stopping. As long as his money is in the online account. Some gamblers try to deposit money into gambling with their bank cards. That is, when the gambler loses, he can continue his gambling regularly. That is why gamblers are more likely to become addicted to online platforms.
Rightly said online gambling has become a serious problem nowadays especially among the younger generation who have less control over their gambling, and even if they lose they want to win more which pushes them towards more addiction. Various online gambling platforms through the internet and smartphones attract users with tempting offers and advertisements. Many people become addicted to online gambling in the hope of earning more money in a short time.