If there is someone who wants to start a dog walking service, but they don't have the capital to do so, I can lend them the money with a promise from them to pa

If there is someone who wants to start a dog walking service, but they don't have the capital to do so, I can lend them the money with a promise from them to pay me a share of any revenue. My money goes to create a service that real people get benefit from (their dogs are walked) and they pay for that service with a medium of exchange that represents their own labour (fiat money). I get something in return for my capital, and the world gets a valuable service. Bitcoin does not offer that. The only return it offers is the hope that tomorrow some other people will pay me more to take my bitcoin, in the hope that some other people will pay them more the day after to take the bitcoin, with the hope that .... you get it.