Sitters, what's the draw for doing THS?

So I'm just getting the hang of this service - owners pay a membership to have their pets and houses looked after. Sitters pay a membership to get accommodation in a new location. But what's the draw as a sitter? You don't get much of a chance to do sightseeing if you're new to a place, as you're tied down if you're looking after dogs (I suppose cats or plants would probably give you more freedom). If you're from abroad, you'd even need to pay for travel.

I've just browsed this sub a bit, and it seems there are mostly sitters here - and you all seem super eager, but what's in it for you if you're not paid, and even paying a membership?

Isn't it better to do the same and get paid for looking after a house and pets through a service like Rover?