The one tangible usecase is perhaps booking things. But, personally, I don't mind paying 5-10% extra by going to a local store and speaking to a real person. Or perhaps intentionally buying ecological. Or whatever. What is life if you have a robot optimize everything you do? What is left?
We think of chat apps, like WhatsApp, as being ways to communicate with people, which is a nice way of saying they are protocols. When you want something, you send a message, and you get an answer, just like with HTTP, except the endpoints have been controlled by meat. With OpenClaw, the meat is gone. Now you can send a message on WhatsApp to schedule a date with your spouse, their OpenClaw will respond with availability, they'll negotiate a time and place. We've replaced human communication with an ad-hoc, open-ended date-negotiation protocol, using English instead of JSON as a data-interchange format, and OpenClaw as the interface library.
You can say "make an appointment at my dentist" and even if your dentist doesn't have a website, the bot can call up and schedule an appointment. (I don't know if OpenClaw can do this now, but it seems inevitable.) In other words, the (human) receptionist is now an API that can be accessed programmatically.
The price is high now but will get cheaper, especially when compared to the cost of human labor.
Having said that, it sounds like an isolating and boring way to live.