That's why the venture capital industry exists, though -- to get reasonably-quick returns on their investment, at a higher rate than just putting their money in

That's why the venture capital industry exists, though -- to get reasonably-quick returns on their investment, at a higher rate than just putting their money into an index fund. If you're not going to potentially give them back 10x their investment in one big lump sum, you're not worth it to them. It's also why VC deals are generally structured as stock purchases, rather than loans that expect repayment. They're genuinely not in it for slowly raking in small returns over the next 50 years. (And then, of course, they spread their investments out so that the one big success that gives them 1000x their money back pays for all the companies that flamed out chasing inadvisable growth.)