Sorry, why do you think it's a rental hub? It's not a rental hub, you're simply giving Bird riders consent to use your property to drop their scooters off (as opposed to them dropping their scooters off on a random person's property, which bypasses consent and is far worse). All of the rental happens between Bird and the rider, you're just giving people permission to leave scooters on your lawn. It's an opt-in rather than opt-out system, which is how it should be.
It is a hub for people to collect rental bikes. You are giving people permission to use your private property only if they have a specific commercial relationship with a business that you also have a specific commercial relationship to, which has a lot of differences to residential use. I'm not an expert, but I'd be pretty stunned if e.g a standard home insurance policy was willing to cover you under those circumstances.