I think maybe they are just referring to the fact that in that era pretty much everyone had to build their own "framework" to get a big web app up, because there weren't a lot of established choices.
This is what I meant, apologies for being cryptic. Web/JS development was absolute chaos, it just so happened that Facebook & Google won the day and we've converged on some "standards" in React/Vue/Angular, and I use that term very loosely.
