On the other hand, why would you want to offer a coin for collateral which is as stable as the borrowed one, and two coins for one at that? To me, it makes no financial sense
There is one reason.
I can give here BNB as example.
BNB hodler profit:
1- IEOs
2- Airdrops -
https://www.binance.com/en/support/articles/84d5325cf7ef4e468c1a6abd1b989dfe3- coin voting airdorps
4- delegating - soon
It all sum up to 60% annual ROI (quantitative ROI) if you dump all coins from activities back to BNB as soon as you get it -
https://bitcointalk.org/index.php?topic=5208144.msg53361035#msg53361035The only reson why not take part in it is currency risk that you can avoid by borrowing BNB instead of buying.
Many coin are necessary for various activites.