Solend is just some random lending market that I--despite being in this space full time--don't think I've ever heard of... supposedly it is similar to AAVE, but on Solana? Just because something happens "in more and more mainstream chains" is meaningless: the chain on which something is running is unrelated to whether it is a good idea or not. I want to be very clear about this: I highly doubt that any normal person CAN do enough research to safely manage loans or borrow and invest with leverage, which is what these lending platforms are for, but that doesn't mean that they are fundamentally broken or are scamming people.