Why do houses have shingles and slanted roofs, but most other buildings have flat tops?

Question

Why do houses have shingles and slanted roofs, but most other buildings have flat tops?

In: 8443

Answer 1

I watched this (https://youtu.be/QW0ydAMVQ2w) that delves exactly in to this topic but it’s not an ELI5 video per se