As a devloper, I have never used S3, despite, of course, heard thousands of times of it. I'm kind of traditional: "Cloud" still means "just another person's hard drive", and "serverless" means "just another person's computer" for me. Having a feel for privacy, I still run a NAS at home, and it's terrible: I really appreciate the amount of work put into S3. Somehow, as a developer, I was able to avoid all that fancy cloud stuff. I prefer self-hosted, but I'm bad at finding good arguments which support my point nowadays :-/