Salvadorians and anyone that hold BTC could borrow from themselves at 0% interest.
Bitcoin is legal tender in El Salvador, and Salvadorians don't have to pay capital gain taxes on their Bitcoin gain either. That is the law of the land. The government of El Salvador created an application for Salvadorians to use if they don't have enough funds to open a Lightning Network. Still, if people are smart, they can get incoming channels for free, if they ask, or pay a minimal fee to services like Coincept and LNBIG. And the software or applications are many, from complete to remote mobile nodes.
Once Salvadorians have their money in Bitcoin, they can become their bank if they decide to do so by relying on the power of self-custody applications. And now, they can join the global economy and enjoy its benefits, all thanks to Bitcoin and its killer application, the Lightning Network protocol.
And now, thanks to Bitcoin's sidechain, RSKsmart, previously known as RootStock RSK, and its decentralized application and exchange (dApp & dex). Now, people around the world can borrow from themselves at zero percent interest and become their private bank, and the best part is that you won't have to pay high transaction fees thanks to RSKsmart bridge with Lightning Network. It means users around the world can make use of Zero Interest Loans Protocols without having to worry. For Salvadorians, it means they can move their money freely, and in a country where the minimum wage is $350.00 or less, where every penny counts, having a line of credit not from a bank but their own BTC holdings is a miracle come true.
Bitcoin is the King, and it will do everything financially related. It won't do it all at once but in cycles, and thanks to Sovryn dApp, now everyone that holds Bitcoin can have their line of credit and enjoy the latest technology when going about; Lightning Network.
RSKsmart is the most decentralized Bitcoin sidechain in the market today that is EVM compatible. The bridge between Bitcoin and RSKsmart is protected by PoWHSM technology, which you will have to learn and research on your own.
Many developing nations don't have well-established bank services where the informal sector can get loans at reasonable interest rates. Having a credit card as a citizen in those nations is indeed a privilege, not a human right; the informal sector is forced to borrow at higher rates from loan sharks. Bitcoin fixes that with Sovryn Zero Interest Protocols.
You don't need to buy the SOV token to enjoy the Zero Interest Loan Protocol, and you must have rBTC to pay for Smart Contracts calls which means you don't need the token for anything, so you can enjoy its features without having to buy yet another shittoken.
Zero Interest Protocol is still in the waiting list phase, meaning you must sign up and wait in line to use the features. The protocol is not open to the general public yet, and developers could find issues, so don't lock up the Bitcoin you are not willing to lose into the contract.
