Most games online require devices with high specifications and good internet connection to run it properly. While many gambling games can be run with low end devices. That's the reason why I prefer online gambling rather than games online. More over, most gambling games are simple.
This is the typical answer most of the gamblers I asked about this. It is true though since it is really minded wrecking sometimes playing games especially ones with puzzle parts in it. Some also say that you can't earn money from online games while you can in gambling, it is half true since we already have esports and tournaments in it. I think gamblers can play games to pass their time but I don't think that that will be their alternative in gambling since it is hard to shift that quickly from gambling to gaming.
If you will follow the necessary gadgets to have a really great gaming experience would require you a hefty amount of money. While, online gambling like dice would only require you to have net and computer or laptop or smartphone. Not so much hullabaloo involved. But I think it is all about the preferences in life. In what path are you satisfied?