If you have a car, why would you take out a car loan? If you have a house, why would you take out a mortgage? If you have a rental property, why would you take out a mortgage against your rental property?
Probably the most analogous to most loans taken out on this forum, if you have a stock portfolio, why would you take out a margin loan?
Answer the above questions, and you will understand why someone with collateral might take out a loan.
If I have a car I will not ask for a loan to get a car why should I do this. I can see the collateral is like insurance that the money will return back to the lender but from my point of view I see the collateral dose not make any thing. I can not take money unless I have a big amount of collateral so If I have a big collateral I will use it for my profit making a good money from it.
Thanks