@Liv My house was a new build I designed, and I live alone, so it's a modest size, with just 2 bedrooms, mine and a small guest room. I originally thought that room would be for family and friends when they came to visit, and it still is, but it sat empty most of the year.
A friend from Canada has come to stay several times, and she was an Airbnb host. She kept telling me I should Airbnb that room, that solo travelers would love it (there's only space for a single bed).
It also lent itself well to Airbnb, as the bathroom opens directly onto my bedroom on one side, and the guest room on the other. So I can easily lock off the door to my room and the bathroom becomes an ensuite solely for the guest use, me using the downstairs bathroom.
The upstairs where the bedrooms are is accessed by an outside staircase, with locking doors to each bedroom off the upstairs balcony. So guests also have a private entrance to their room.
I procrastinated listing it for a couple of years, then decided to go for it.
As it only accommodates one guest and the tourist season here is only about half the year, it isn't a big money maker, and I never assumed it would be. Until Covid hit, it earned me enough to finance my annual 5-6 week summer trip to Canada to visit my daughters and grandkids, along with the things I buy up there to bring back that aren't available here (like nice cotton sheets).
So it was a combination of making use of a space that was languishing most of the year, thinking it would be fun to host travelers from all over, which it has been, plus earning a bit of extra income.
And as I don't want a full time roommate, and want to be able to have it available when friends and family come down, short term rentals were the perfect option.
I certainly wouldn't do it for free, like couch surfing, as pulling strangers' hair and soap scum out of the shower drain could hardly qualify as a pleasant hobby, but because I'm not dependent on the income, it makes my hosting pretty stress-free. I.e. if a guest needs to shorten their trip for some reason, or cancel, I'm pretty easy going about offering to refund them, and I've never had hassles with guests about that, or really anything else.