I don't know if they really exist anymore, but I did stay in an honest-to-God B&B, long ago. I cannot remember where it was or why I was staying there. But I do recall that it was a rustic, quaint, actual residential house, that had many bedrooms converted into guest rooms. And my room was well-decorated (nothing like a Motel 6) and it had a very nice featherbed with flowered comforter, and all sorts of comforts just like home.
And of course, the key to a real B&B is the breakfast. When I awoke in the morning (I only stayed one night!) the hosts were downstairs, serving a delicious homemade buffet breakfast spread. It was a fantastic time.
The hosts were very personable and kind, and I felt very welcome there. It was, of course, regulated just like any hotel in the hospitality industry, so it went without saying that these hosts carried insurance and had a lot of rules to follow, letting strangers into their "home" which was obviously, 100% a business at that point.
Yeah, I don't know if there are any bona fide Bed & Breakfast hotels left in this world. AirBNB has certainly ruined the traditional terminology for that sector.