I don't think he will ever repay, at best he will say he was hacked and he was not the one who took the loan.
I see also lenders are changing their policy to not accepting accounts as collateral, that is a wise decision as let's be honest the accountsa re not really worth it, anyone can make multiple accounts and upgrade them and take loans and default. Best collateral is an altcoin that has been established well and would easily fetch to the lender the value of his loan plus some extra for his time.
You are 100% right accounts should not be taken for collateral those are just sold and bought like cookies on this forum
if the borrower will fail to repay the lender will have some hard time to resell it if he can not sign messages from old staked wallets and the risk that the account get negative feedback is high and maybe it will never be removed or at least it will than mark as "sold collatera"
altcoins is the best choice but do not jump on new altcoins use well known ones to make sure you can recover the money .