I always say hello to spiders and geckos when I see them in our home because they eat pests like mosquitoes, termites, and cockroaches.
They are our welcome guests.
... and a nice snack for the cats.
If they're outside, whatever.
If they're on my house, I destroy the webs, rarely ever kill the spider because they're hiding in the day time.
If they're in my house, they trespassed into my realm and their lives are forfeit. It's not like there aren't millions upon millions more of them outside. For me this is true of any insect (and yes I know that spiders are arachnids...). It comes into my house, it is my mission to destroy it.
i let them live if they impress me, most i kill.
also depends how quickly they move - a fast spider is hard to transport
found a dysdera in my closet while spring cleaning, it was so striking i had to let it live so i could see more of them. i googled it after to learn what type of spider in my area looked that way and if it was venomous- only then did i get to see its fangs! if i knew how epic this spider was i would have kept it as a pet.
Letting house spiders outside is usually a death sentence to them. Just let them hang out inside so they can eat all the bugs that will cause actual problems.