Case in point with JS libs and the following line: "You are going to start adding modules and eventually you're going to have a whole ecosystem". This happens with individual JS-built products using libs, but definitely does not happen universally with most JS libraries. Take React, the first comparator referenced in the post title: its ecosystem is entirely 3rd-party addons and the core is focused and single-purpose to this day. They've added a lot of internal complexity to their vdom implementation which adds code bloat, but it isn't what this commenter is describing.
Vague comments like this never apply to all cases (often apply to no cases). It's a lazy comment that contributes nothing without being specific to this new library. You need to read the code and develop some genuine insight to have this type of commentary.