I don’t think it nullifies anything, rather to think it raises further issues. Proof of stake means to use money to ‘stake’ so you get get more money. Just from that simple crude explanation it looks like Ribaa. Now I’m not saying outright that it is, but that would be the first potential objection.

Now looking at whether it is Ribaa or not, it really depends on the implementation of the PoS. I’m not a specialist in PoS, so confirm what I say further, but with protocols like Ethereum, you lose access to your stake as a result of the stake, and you even have to wait in a ‘cue’ before you can withdraw it. Losing control of your money is one of the characteristics of a loan. It’s no longer “yours”. The fact you have to send it to an address you are not in control over is what a loan would look like on a blockchain.

However, not all PoS are created equal apparently. Apparently, and Allaah Knows best, you have to verify it, with Cardano, when you “stake” your ADA, you don’t actually lose control over it. It’s staked with a staking pool, but it doesn’t leave your wallet. So you could spend it immediately, as I was told. If that’s the case, then it’s not a loan.

So looking at the above, ie would “seem” that ETH is a loan that gets you profit (ie the definition of Ribaa) whereas ADA seems to act like a business partnership where you use your “reputation” to gain rights to profits owned by someone else who is doing the hard work of validating transactions.

The one argument to be made that ETH staking is not Ribaa is the fact that you have to actually do work in order to gain profit, ie profit is not guaranteed. That’s important, and you could lose your money if you misbehave, also something that is not a characteristic of a loan.

But the issue with PoS, for those who have issue with PoW is that there is even less real world tangibility than ₿itcoin , so if they have issue with BTC, then PoS would be worse.