Crypto as the best payment method? Why?

Nowadays when I contact a seller on this site in 70% they only accept cryptocurrency. Why is it good?

I know PayPal isn't the best alternative because of scammers can get back their money. I understand that point but there is, for instance, Skrill or Bank Transfer. I know Bank Transfer takes so much time. But why cryptocurrency?

It is the MOST unstable payment method. A year ago 1 BTC worth 17000$ but now it is only 8500$. 10000$/BTC. Too much.

For instance, I can't exactly calculate how much I need and I convert 100$ to BTC. After that, I buy some goods for 60$. I have 40$ (0.0024 BTC). I have anything that I wanted so I don't spend for anything and boom. I had 40$ but now I have only 20$ (0.0047 BTC). I lost 20$. Ok, it isn't too much but who had 40000$, he or she lost 20000$.

THAT IS ONLY AN EXAMPLE.

Someone, please tell me why it is good to use an unstable, unofficial payment method?

As a former seller on MPGH, I mainly used Crypto because people couldn't chargeback. So it meant I could accept orders from noobs (noobs usually tend to scam sellers by charge backing). Not saying being a noob is bad, but noobs aren't trusted. If they get banned on MPGH, they don't care because they haven't built their account. Another big reason was that Sellers PayPal accounts get limited a lot. It becomes annoying to deal with that process. Meaning a lot of money gets stuck in a PayPal account forever.

You can find price conversion of USD to BTC here: http://preev.com/

Cryptocurrency prices are unstable (as we are in a 50%+ drop). However, people believe in the long run 1 BTC will be worth 100k+. Sellers who don't keep their BTC, most likely exchange their BTC for USD right away using a trusted exchange company. Even though it seems stupid that a customer converted their USD to BTC and the seller just ended up converted the BTC back to USD, it still means the seller's PayPal will not get limited and the customer cannot chargeback.

How to buy BTC? Well you can use the MPGH forum to buy BTC using PayPal. There is usually a 15-20% fee. Otherwise, you can use a trusted exchange. You have to tell us what country you are in, before we can tell you an exchange you can use. The most popular real life dollars to BTC exchange, available in the most countries would be Coinbase