@Rod1751 A host can't charge 0. Airbnb doesn't allow that. All a host can do is offer a discount. But guests asking for discounts and freebies is really annoying to hosts and most hosts consider those requests to be red flags and the harbinger of a difficult and entitled guest.
@Rod1751 Hosts either fix things themselves or have handymen, plumbers, electricians, etc. they rely on. They wouldn't be interested in letting a guest "fix" things, because guests are complete strangers and letting them muck about fixing or changing anything in the rental could just end up being a disaster.
I can assure you I know how to fix toilet issues. It's Homeowner 101 stuff.