Well RCs would be the go-to, and that could actually play a bigger factor than we see now. If the blockchain grows, then RC costs will grow with it. If we have both growth and RC pools are ever implemented, then I'm positive a market will surface for the large stakeholders to rent out RCs and make a passive income with their stake.
That's a lot of ifs, and I don't think it's the only solution, just something to think about.
I guess we shall see...if we ever get there.