Based on my observations on the Lending subforum, it's mainly requests from trolls that are not serious or just plain scammers.
https://bitcointalksearch.org/topic/123-5368349
They would post some sob story, then upon being called out by the seniors, start to show their true colors. Happens with the sock puppets or alt accounts.
If you're a lender, the safest and easiest collaterals would be highly liquid crypto (e.g. ETH/ BTC/ LTC). They don't take too long to transfer and miles better in terms of fees + anonymity.
Secondary would be physical items, but appraising them is difficult because of the shipment time and also the need to find the right buyer.
Accounts, very rare because they could almost always be recovered by the owner under the pretense of "getting hijacked/ hacked"
According to my research so far, I think best way to get profit is to get interest in usdt. Since it doesn't depreciate in value. Moreover loan must be given in usd, so you get your money back. If loan is in btc chances are you may lose money in return of loan.