I hike in the woods and get facefulls of spider webs and spiders landing on me all of the time (yes, I scream like a little girl.) However, I have been called hopelessly optimistic and so I have to share my hopelessly optimistic view of the huge spiders....
At least you see them in time.
The brown recluse spiders that bit me on the bootie and caused such a horrible problem for me... they were tiny. I never, ever saw them. You can't avoid what you can't see.
So, at least you can see the big 'uns and have time to run away screaming before they actually cause you physical harm.