Well you tackled something that is a huge issue in gaming, as far as I'm concerned.

You said most of what I have to say on the matter - I've been caught in the web of one of those Asian games you mention, specifically Metin 2. Not that I liked it particularly, but I had a bunch of friends playing and Gameforge gave me some coupons for free stuff because I used to be a moderator in one of their forums, so I started playing, and back in the day it was not that bad, lots of people who didn't spend a dime and enjoyed the game just the same. At some point that mechanics you described kicked in and it all went to hell. Not only do they make you gamble to find an item in a box, but they actually give that item a time limit so that you have to start over every month. I was lucky enough to have some better judgement and let it go, but I wasn't build for PvP games and I have no competitiveness while playing online. And it took me some time before I stopped trying and grinding anyway. And I'm lucky enough not to have money sitting around that I can waste on such things.
I think that games like that should be outlawed, especially in countries where gambling is illegal. This is a controversy that's been dealt with over the last few months, what with EA, Battlefront and loot boxes, but has been actually very much an issue for years before that.
On the other hand, though, I have no problem with that "benign" sense of gambling that you talk about. Opening a chest and wanting to find an item - or any good item - is one of those things that give longevity and meaning to action rpgs and games like that. I never really liked games with fixed loot. "Random" is one of those good things that stay good as long as money isn't involved.

I guess we should try to educate people to ask themselves a few things, when they get trapped. That's how I managed to get out. Specifically:

1. What am I doing with my money and isn't there a better way to invest it? So i spent 200 bucks on virtual boxes, that may or may not give me a virtual item, that may or may not help my virtual character defeat other virtual characters, as long as they haven't spent more money than me. What if there was something else I could have spent those 200 bucks on that is more tangible and constructive for me?
2. What am I doing with my time and isn't there a better way to invest it? Same thing basically. When I'm tempted to play such a game I remind myself of all the great games that I still have to play. I remind myself of the games that I love - TES: Whatever, The Witcher, Deus Ex - games that have given me something on an existential level that I'll never forget, or that I've loved so much for their vastness and their content. Am I still convinced I want to waste my time on the same game grinding for hours a game because "I have to buy that box"?
3. Most importantly: are my efforts actually being rewarded? If a game is entirely based on the money you spend on it, even when you find that one item you're looking for you're not really proving anything about yourself, you're just proving you have deeper pockets. So you spend hours and hours grinding to find money, and items, and stuff, but does it give you something back?

So yeah, that's it. Great video and sorry for dropping a wall of text under another one of your posts. You just have that effect on me dude. You should start doing gameplay videos like all those other guys, so I'll get bored after 5 minutes and get out of your comments section :D