> That's a semantic detail based on the choice of build from source over binary distribution.
It's not, AUR is more like GitHub, anyone can upload content there, not like a proper repository where things are reviewed, verified and cared for.
You're complaining about "curl https://random-website.com | bash" being "a semantic detail" while it's a major difference in how much trust you can put into it. If you don't trust random-website.com, you shouldn't trust AUR packages. But very different from BSD Ports or Arch's official repositories.