Yes, if all you consider by "bloat" is how many kilobytes of javascript you have on the page, AMP is not doing well. This is a crucial mistake in this post. In reality "bloat" is more than that. It also refers to whether there's active javascript slowing the browser down, whether resources are cached etc.
The purpose of having these small plugins that enable functionality is that they are all individually cached by your browser for a good amount of time. Any Google user would have them cached as they are all using the same reference that any other AMP page would. This is unlike other "bloat" where resources are fragmented and come from any number of sources that users probably haven't hit before. In addition these JS resources wouldn't have been written for a specific experience - which AMP is