Yeah I suppose if you only relied upon zaps that would be pretty weak sause.
Now with Podcasting 2.0 where the culture actually understands what value means, f you tap into that model and scene and culture I think you'd have a node paid for in no time.
The cost/time associated with running a node is absolutely negligible, though. People act like it's a full-time job. It's not. I spend more time constantly clearing out my email inbox than I do fussing over my node.
As far as risk, custodial services being lower risk is laughable to me.