I reckon it's just a difference of how you'd define gambling is? In general I don't think sports betting is gambling, hence why I call it a bet. It can BE a gamble, but it doesn't have to be one. What your uncle did was exactly that, and the same thing could be done in trading imo. Gambling on the other hand? I define that as relying completely on luck, gut, or whatever the hell you want to describe it with. Like full on ofc, imo even betting has that bit of gut in part of it but it's never really used as a reference alone, unlike gambling.

And yes, trading and investing would definitely be different. I'd probably recommend for people who have a 9-5 to just invest than trade.