That aspect could be leaner, indeed, although all those processes put together can easily consume fewer resources than a single bloated program or a web page, especially if they do not include a particularly large DE. The systems I have in mind as references are Debian with Xfce (runs on an old Atom-based netbook, taking 600 MB of main memory altogether), or Debian on a server with a bunch of common services (web, email with related services, XMPP, Gopher, IRC bouncer, authoritative and caching DNS servers, etc), also consuming under 600 MB (under 400 without DNS cache), with CPU load coming mostly from fail2ban, but being pretty close to zero. On the other hand, there are KDE and GNOME, which would probably at least double that resource usage.
To be clear, I brought up GNU/Linux distributions as examples of container-free packaging, and as notable collections of relatively lean programs, but not necessarily as an example of the combined systems being particularly lean themselves. Though then again, compared to something like recent Windows versions, perhaps even the Linux-based systems with larger DEs would seem lean.
It really depends on the distro. But of course there is the same risk as ElectronJS: getting a huge Ubuntu distro that ships with everything is faster than building up from a lean distro.
