AFAIK Amazon are running a lot of actual production loads on AWS. Dogfooding can be extremely valuable, especially if a massive portion of your staff have the same profession as your target market.
I've been using Google Cloud in a new role I started recently. There's definitely some parts of GCP I like, but whenever I use the Web Console I get the distinct impression nobody at Google actually uses it. If they did, I'm fairly sure all the annoying little warts I encounter would not exist.