I have done very similar experiments and I have a few thoughts:
1) I think that everyone would agree that spending this much money on chests would be a total rip off, and I hope nobody is doing that. I bought a medium amount of platinum the first few hours of playing the game, and that was it. There was no point beyond that. The microtransactions in this game is even many times worse than you find in FIFA Ultimate Team. Atleast in FUT you can trade what you dont need off, to earn money to improve your team. Here, theres no such option, only salvaging for a hope of some great crafting item in the future.
2) If you increase the drop rate of weapons/items, eventually everyone would run around with OP weapons/items, which would ruin the game. Imo. Even though everyones screaming for an increase in drop rate of usefull items, I am not sure that would be a good idea. Maybe that only benefits me who already has mostly the best items for every class, but if everyone ran around with Sulevin Blade or the likes, would it really be any fun? Maybe for a short while, but not in the long run.
3) Considering that, the loot system still needs a complete overhaul for multiplayer to stay interesting. I don't mind the chestdrops really, it is all basically down to luck and I believe that the OP has been unlucky, but after you have recieved a decent amount of OP items for all characters, there really is no reason to play the game anymore. You have completed multiple runs on perilous and to get any upgrade to your items you have to open 200-300 chests for just a single upgrade or two, if you go by the OP's stats/luck/drops... The grind is real. There has to be more options, and I think there might be a solution in doing something with the treasure rooms maybe. Or something completely different. Create an option where you can actually get something usefull while actually playing the game.... Also they really do need to make a lot more content and a lot more challenges, but thats a different issue alltogether.
Just a few of my two cents.