Yes, I think a reasonable position would be that if you perform staking by self-hosting then you're providing a service. An example is getting paid for running a machine on the Ethereum network.

If you pay money in now and get more money out later, and someone else runs the machines, then it's just a loan.

Then there's a question of where to draw the line with cloud hosting, and I have no opinion about that. Someone will sell a service that's barely on the right side of that line, wherever it is.