Earlier quoted context omitted.
One argument is that Javascript-in-the-browser has advanced a lot and there's less need for a build system. (ex. ESM module in the browser) I have some side projects that are mainly HTMX-based with some usage of libraries like D3.js and a small amount of hand-written Javascript. I don't feel that bad about using unpkg because I include signatures for my dependencies.
npm is a package manager though, not a build system. If you use a library that has a dependency on another library, npm downloads the right version for you.
I guess if your problem with npm and bundlers is you don’t want to run those programs, fine? I just don’t really understand what you gain from avoiding running bundlers on your local computer.