there are some users who just played for a very long time and they ranked to Platinum by wagering over a very long time. There are also legal methods to rank up with minimum losses, if your goal is to rank up. (It will take much less funds, than just playing 3rd party Slots and losing tons of money)
On the other hand, Eddie (one of the owners) mentioned in one of his Streams that most of the Diamond players are from Russia and they have huge pockets.

Gambling for a very long time very consistently will obviously get you to a higher level. If you for example started 2 years ago, and gambled with 50 bucks per month, made into 1000 dollars per month wagering which should be a lot higher, you can do as much as 2500 dollars but let's take it to 1000 dollars, you would have gambled 24 thousand dollars, all with just losing 50 dollars per month.
It is obvious that you can get to a higher VIP status if you just continue from right now, just keep going as much as you want and you will get there, aim at not gambling too much away all at once, and keep gambling on good odds and you are going to end up gambling a decent amount for sure. This is obviously for reaching VIP status, and if too many people suddenly becomes VIP they will make it harder to become VIP, since your aim should be gambling, and VIP should be side effect.