There are different types of gamblers depending on what they play. Some gamblers are rounded and play all kinds of types possible but there are those who only stick with one type.
For example, one could just play slots while one just sports betting. My question would be which one do you think is more addicting? Slot machines are more rapid and you can play it more consecutively because it is fast unlike sports betting where matches take time. You might get addicted on sports betting more if you enjoy analyzing things and winning it might give you some pride for your skills. Not to mention that if you are a fan of the sport you are betting on, surely you are emotionally invested in the sport therefore would want to follow it and bet on it many times.
Now, what is more addicting? Slots or sports betting?
They are both equally addictive to those people who are predisposed of becoming addicted.
Although it also depends on the person, I think. I am not much of a sports guy, so I do find slots more fun. But I can see a person becoming more easily addicted to sports gambling if he/she was a sports fanatic in the first place.
I get bored, personally, if I stay with one game too long. Even slots becomes more boring than sports betting if all you do is play slots all the time. It's like having a favorite food but eating it everyday will get old fast.