I think lending will always exist even in a bitcoin world, especially the more it matures, if we get to a point where bitcoin is this global money/settlement network then your annual appreciation for holding it is tied to global GDP, improvements in goods and services over time, so those with capital will seek additional risk

The same can be said for moving Bitcoin into an L2 like lightning, people will do it to go and capture the potential yield, and maybe there will be other L2s that attract different people with different risk appetites, so maybe that sets the new Bitcoin lending rate and then people will need to compete with that rate to get people to borrow their bitcoin

I think most lending will rely on a trust model, even with bitcoin, because over-collateralized trustless models don't always provide the most efficient return on investment.

So I see banks/federations and other forms of multi-party collaboration to match capital, risk, and time preference playing their part in this and you can have these products enter markets it could never before