OP here! #1 was my motivation, though at the moment I'm definitely feeling like #4 played a role.

My rationale was that crypto just sitting in cold storage could only gain value if the underlying asset appreciated which is effectively currency speculation. By storing it in a crypto "bank" my money could be working to generate actual value via. liquidity and loans akin to a real bank.

If the money was earning a modest amount of interest it didn't feel like as wild of a risk. Even if the exchange rate to USD is unstable I can still see the amount of crypto going up each month.