There are many petitions about removing various features into ‘Core Plugins’. And, that should be done with: Customizer, REST-API, XML-RPC, Comments, Links… This will make maintenance easier, and CP core lighter.
But, the main thing related to the Core Plugins would be an extra step during the CP installation - when everything is set up (database, language and admin account), a new screen will be presented to select core plugins to install.
Also, the Plugins menu should be expanded to show the Core Plugins page where the Core plugins can be installed and removed, and not to be mixed with other Plugins.
I had always assumed that the core plugins would be decided upon during install.
I think it would be OK to show a user a screen where they can choose a “custom install”. Software always gives me this choice when I install it, many times I just scroll through the choices and go with the default.
It also seems good to offer different packages to download.
But, I don’t know if a package with plugins that aren’t used will be any lighter on the front end or not, since I am just a “user”.