Maybe you can gamble for fun depending on anyone's perspective. You might see gambling for fun when you are betting with free bet you have been given by the casino you are using to gamble. Another person can see gambling for fun as trying to use lower amount to gamble with your risk management maintained.
This can be frequently since you are not using so much funds to gamble at ones. Everything depends on how we see the words "gambling for fun" I can only gambler for the fun when I have made so much profits from gambling and I have trying to test my luck putting some amount into betting to see if I can still make profits. I think everyone has there own definition when we talk about gambling for the fun.
I like the fact that you pointed out different reasons and perspectives of people concerning gambling for fun. Well all those scenarios are right, there are more to these reasons but one thing that is constant is, even if you gamble for fun for a while (more than 2 sittings) and you keep experience losing strike throughout your gambling session without any portable win, trust me you'll get tired of gambling. Even if your intention was to gamble for fun. In gamble no matter your intent, wining has a way of motivating you to play more or lightning up your mood when playing for fun or for making extra cash.
Indeed and that experienced gives you the confidence to keep playing for more, though it's a case to case situations where some might get addicted and some might gain knowledge it's on the gambler itself if you they'll take that experience and use it for their advantage, but for those who turned things into addiction most of them will either call it a scam or will surely regret participating on any types of gambling activities that they've involved with.
Those who make terrible financial mistakes and put the blame on gambling or call it a scam process are likely to do thesame to other opportunities that seem like using money to get extra money eg cryptocurrency, trading currency pairs. Because you gambling without getting addicted is a function of discipline. It's a state of mind that you alone can build for self, so if you don't learn to control your emotions you end up messing other things up because of your mindset.