It's not even really collecting it all from what I can tell, but the fact they gate off content and give low drop rates to try and get you to pay for more loot boxes, which still have a low chance of dropping what you want.
So, are all these people complaining about lootboxes actually playing the game because they enjoy it, or are they playing in the hope that they get some random, rare item that only other people who even care about the game will be impressed with? Not possible to get every special item in a short period of time? That’s too bad. I can’t imagine getting so worked up about something like this that I would create, edit and post a video about it...
While they are mostly "Just Cosmetic" many of the items have a unique and cool appearance, some even effect gameplay. Now say there is an item you really want (I don't know if they are class specific), well you gotta deal with a random loot generator for it to drop, but you're only allowed 3 chances at getting the item per week till the event is done, unless you pay real money.
I'm playing Overwatch right now, trying to earn the few Holiday skins I'd like. The only limit on how many boxes you can get in a week are time constraints, and ALL boxes have a chance to drop the Holiday content. In contrast with Destiny 2, you're only allowed 3 holiday boxes per week, dramatically reducing the chances of getting what you want, and much, much worse for those completionist.
I myself refuse to buy any "Loot Box" or "Microtransaction" and hate to see how much they are pushing them in the current game marketplace. To the point it ruined Star Wars, and Destiny is under the same flack for how hard they are pushing it...
It's been said Battlefront 2 was the most egregious, while Destiny 2 is the most deceptive.
Another good video on the subject, though tend to dislike the host because he comes off as a pretencious prick. https://youtu.be/zTsWd4M53JU