Nothing you're describing applies to the scenario of "download, then execute" either, which is the alternative to "pipe to bash". Anyone who's willing to read

Nothing you're describing applies to the scenario of "download, then execute" either, which is the alternative to "pipe to bash". Anyone who's willing to read the script first, or verify PGP keys, or whatnot, is perfectly capable of doing so even if the instructions tell you to pipe to bash. But the overwhelming majority of people don't do that.