This is something we are going to have to LEARN. There can be no usury with a fixed money supply.

You cannot lend to JP, and get 5% of bitcoin back. It runs into the hard limit of hard money.

There is one big caveat. We still have the dollar. And its amount of units is still going ballistic. So, if we talk about 5% in dollars, you can do that all day, any day.

I would love someone to do a calculation.
There is a point where you have enough bitcoin. Enough for the rest of your life.
And if, say, bitcoin went up 100% per year,
you could sell half your bitcoin this year, and next year, the half left is worth the same amount,
and you just keep selling half for the rest of your life.

And the never sell thing really has to do with our financial system melting down. Sell bitcoin (going up) for dollars (going down) is fairly stupid in the long term. (in the short term it can be lucrative or just allow you to live). Providing liquidity is nice, but you are betting the financial system will be there next week.