Yes, the evaporating cools down the room, though I can't say I ever noticed it. In terms of energy efficiency compared to a dryer, it's much better in summer, and not much better in winter, though you get a humidifier as a freeby.
Yes, it's a chore, a full load takes about ten minutes to hang, and it's real boring work.
There are a lot of different buildings and climates where you will have problems hanging laundry indoors. It definitely can cause mould, it definitely is a health risk without paying extra for dehumidifiers. And dehumidifiers are not great for the environment either as well as costing extra.
So two good reasons to hang out rather than in.
Plus hanging laundry outdoors dries them much, much quicker too. They can be dry in 2 hours most of the time, compared to up to 2 days inside.
That being said : I see what you mean. I grew up in France ( dryer don’t exists ) and it’s easy to dry stuff there. Except maybe in winter.
Now I’m in Louisiana… yeah, it’s humid. But if you put things in the sun it does dry super quick too.
Yes, and most of that drying happened outside. Also, moldy rooms and people having to deal with mold were a thing in the past.