It's amazing how consistently HN people underestimate the workload involved in basically any software product, and how often this blog post is relevant: https://danluu.com/sounds-easy/

> I can't think of a single large software company that doesn't regularly draw internet comments of the form “What do all the employees do? I could build their product myself.”

Products are nearly always more complicated internally than it appears to the user. Indeed, often the very ease of use that you see as an end user is because of higher complexity on the inside.