Yes, this was the original idea. But the world has changed since then while the current token based system is neither cheap nor predictable.
When we check back we see transaction cost of $2 per transaction for Storj but we have also seen even more crazy high gas fees:
Additionally to that there are the handling and transactions cost for the receiving SNO. It is easy to forget about those, but they exist. I see them every month.
It is easy to check the difference between what I have actually received, what was sent and what would have been the outcome if it was sent the via a specialized payment provider. And I can tell you that for the last payout circle I have lost additionally 3,5% to 4,2% of the $ amount sent due to crypto currency craziness compared to what it would have been when sent the traditional way. So on a $100 payout this means $4 loss equivalent to 2TB egress or 2,66 TB of provided storage.
So no, the current system is not necessarily cheaper its cost may just be hidden.
Storj was even forced to introduce a minimum payout for the current system due to high and unpredictable costs and they were also forced to develop solutions for testing different blockchains and zksync because the transactions costs were high and unpredictable.
Nobody would prevent Storj to keep a minimum payout threshold when using a payment provider. But instead of what it is now, it would be stable and predictable.
Additionally I have mentioned more than once that I would be happy to bear those little extra cost (compared to the cost receiving Storj token) in accordance to what seems to be written in the whitepaper:
I have mentioned that I could easily provide a US banking account number through a payment provider. How much can it cost for a company to transfer money to this? Tell me. I am sure it is not a big amount. I would happily bear it as I am 100% sure it would be lower than what I have to pay today to receive STORJ token, convert them and send them to my bank account. So when I bear costs that Storj has to pay today then they would even save money.
In my view, stablecoins will be very important in the future if you want to pay or getting paid without the risk of losing money.
And additionally even more due to this:
Remember: Bitcoin was invented as currency and a substitute for fiat money, so that people can easily transfer money between them without banks. It has been turned into an “investment” aka casino. The “real” Bitcoin would be a coin with a stable value to transfer money between ecosystem participants to eliminate the volatility from the transaction costs. And this is what makes them popular.