What you said is true, besides that not everyone who gambles will definitely experience addiction because it depends on the level of greed as you said and with their own perspective on gambling, there are two possible different views.
First, with those who view gambling as something that can provide benefits in a short period of time, this perspective factor tends to make perpetrators addicted to gambling faster with other factors such as what you said with the level of greed or always feeling lacking when they have succeeded in winning.
With the second, those who view gambling as just entertainment without excessive expectations in the gambling they do. Usually people like this are wise in gambling, there is no behavior that leads to addiction such as continuously depositing money when they have lost, feeling dissatisfied even though they have made a profit or chasing victory.
You are right, the two types of gamblers you mentioned here are actually true gamblers. For example, if I say something about myself, I always try to keep gambling within a limit and I don't gamble regularly. However, sometimes I do sports betting in my free time. Which is just for my entertainment.
And I always try to bet the smallest amount possible so that I don't face any big losses because I believe that in gambling I will lose most of the time and win very rarely. And to be honest, gambling this way has allowed me to control my losses in the same way I get entertainment from gambling.