When I was three my family lived in Hawaii where “Banana Spiders” (large tarantula looking things) used to get into our beds at night. They don’t just crawl, they kind of hop about (or so three year old me remembers). So, to answer your question I have a standing agreement with the arachnids that inhabit my abode: I know you’re here and that you eat bugs, which I appreciate, however if I see you, game over.

You probably don't live in a tropical country. If you left spiders in your house alone, then within a week the place is filled with cobwebs littered with dead insects. Also, many spiders give you rashes even if they don't bite you. And spiders tend to attract each other.

I kill dangerous spiders in my home if I can't easily extract them. Harmless spiders are left to their own devices.