This is the best, most concise description of how I feel about it.
They should put THAT on the website instead of "An approachable, performant and versatile framework for building web user interfaces."
VueJS - syntax is very simple, you can start using it by importing it in <script> tag, or you can set up a full dev environment with vite, you can use vue dev tools plugin in chrome. It also has a very simple state management system as well as an event bus, if you want to go that route.
and for backend - fastapi.
i never found those "all-on-one full stack" frameworks to be usable.