I work on an SPA with hundreds of screens. We package it using off the shelf tooling with barely any configuration. All of the code and styling is still far under a megabyte gzipped.

So unless it is an all text app, the size of the code bundle is probably going to be quickly dwarfed by the size of media like images, animated images, or videos.

If a site has an SPA with a, say, 3mb code bundle, I think in most cases, that’s not an architecture issue. It’s probably an issue of poor engineering and switching to a MPA is not suddenly going to make those engineers competent.

Check out how bloated is MS Teams web app, for instance.