Almost all package managers have a graphical front end. I'm not sure how that's not "Normal user" oriented. Windows even has a "Windows Store" bastardized version of a package manager,

One that doesn't require root.

A lot of the use cases of those curl | bash scripts are to support non-standard installation, like with unusual distros and user-only. And unusual distros are kind of an unsolvable thing, because people that want them won't want your package manager.

If a user is running a non-standard installation, I would generally assume that they're competent using a package manager.

Typical "curl | bash" script requires root, as it want to write to your /usr/bin, /usr/lib and others. You could trick it with chroot, maybe. And maybe not. But in such case you should to discover all dependencies it needs hard way, as you need to put them in your chroot too.