I think bloat really means two different things. One is the obvious "file size" issue, and as you are mentioning it's quite possible to write small sites even using heavy-weight frameworks.
But a lot of the complaints in this thread boil down to modern sites being slow to run on computers that are only a few years old. If modern frameworks are to blame for that, it's not because they're a hundred (or more) KB. It's because they require the end user to run way more Javascript in the browser and consume far more memory than a site with minimal Javascript requires to accomplish the same thing.
As a random example, Firefox's about:performance page says that the three YouTube tabs I have open are each consuming about 50 MB of my computer's memory. That's obscene. (None of the tabs are open on a video, so this is not the result of storing videos in RAM.)
Also, I did a Lighthouse analysis of the Reddit home page in Chrome (on Desktop, but targeting mobile). The page scores less than 20/100 on performance, and takes almost twenty seconds to become interactive!! The biggest problem Lighthouse sees with the page is not the file size, but the amount of Javascript being executed. There's ~25 seconds of "main thread work" being done in my test.
