You can not stop consuming (neither can the wealthy men).
So deflation have some lower limit (you must pay for food, water, clothes, shelter, drugs (in you get sick), etc.)
Wealthier you are more you consume in absolute even if it is not in proportion compared to poor people (this is the purpose to be wealthy).
The main reason deflation self correct is it discourage investments and favor savings.
Savings = seeds in storage (less risky or no risk at all)
Investments = seeds in the soil to become more seeds (more risky)
The value of money depend on the quantity of goods available: if they increase, the value of money increase. If they decrease, the value of money decrease.
If the value of money increase 3% per year, the economy increase 3% per year. Investments promising more than 3% will be funded (in not too risky), investment promising 3% or less will not be funded.
If the value of money increase 2% per year, the economy will increase 2% per year. Investment promising more than 2% will be funded, promising 2% or less will be not.
Now, if we suppose a 3x risk premium, if the riskless increase in the value of money is 3% and someone promise >10% return for a reasonable risk, these projects will be funded.
If these projects are successful, the overall economic return will be 3%. The economy it is now larger, the investors get 4-5-6% per year (after profits and losses) instead of 3%.
If there are not projects able to return 10%, the growth will fall to 2%. People will increase their savings (they produce more than they consume) until they have enough and a 2% return will start to appear interesting. Then they will start to fund risky projects returning 6% (3 times 2%).
They can take risks because they have other savings. Even if their investments are wiped out, their savings are not and they are able to continue to consume as before.
In an inflationary environment, you are forced to have less saving (because they lose value) and more risky investments. And, because the good investments with good returning are not infinite, you end with lossy investments.
Ok. Let's take the lending - borrowing side of things.
Assume I lend 100 BTC @ 10% interest.
If apart from me and the borrower, the entire economy remains constant, then where will that extra 10% BTC come from? That can happen only when someone looses that 10% equivalent BTC. So it will become a system where someone will have to lose for other to win and it can never be a win-win. Which means that all people can't live happily in such a system
Money value up means less investments, which is ok sometimes, frenetic investment of all sorts of value destructing ventures is not always what the world needs.
My concern was a bit different. Let me rephrase it.
Assume there are total 1000 BTC in the world
I have 500 BTC which I lent to another person @10%. Now where will that extra 10% BTC or 50 BTC for the interest come from in the economy? The only way he can repay the interest is if someone in the economy faces a loss of 50 BTC from which he profits. So are we devising an economy where loss is certain for some and all cannot profit at the same time?
Interest is paid by the borrower to the lender. They don't have to magically spring into existence. It is just like another trade.