You couldn't be more wrong. Maybe if you have 4 plugins this is a workable strategy. What if you have 20 or 50. How on earth do you update any of them cleanly?
It's because of comments like this that I've reserved my opinion about Vim script managers, of all things, for many years. There's no "right" or "wrong," I favor a tightly integrated editor setup where I own my plugins. Further, I don't believe that reaching for a plugin every time you have a problem to solve is the best or only way to extend your editor. My .vim probably has 10-30 third-party script collections, but "upgrade all vim scripts" isn't something I've ever wished to do at the same time. I prefer to upgrade plugins that I know to be active projects after reviewing the changelog, and I do this about once a year.
Is it so hard to relate to the desire simplicity and control in editor config? It's one place where I want to keep the cognitive overhead as low as possible: No forking git repositories to fix a bug in somebody's indent script that's not been maintained since 2007.