I'm not sure about the roadmap of the web modeler but you can view the following videos regarding the web modeler:
You can also follow the modules about the web modeler:
There are also more lectures on this topic, you can find them on: https://gettingstarted.mendixcloud.com/link/module
Hope that helps.
Also good to know: the web modeler is not meant as a replacement for the desktop modeler, so it will probably never get the advanced functionalities of the desktop modeler. The web modeler is initally meant for faster prototyping, to get working ideas even faster, together with the business people.
It is true that the web modeler is still in beta, and is lacking some advanced functionalities.
But most of the basic stuff is there, regarding your example - "a simple hello world app where I can create a table to store data and also add anew, edit and delete button" I believe this is all possible from the web modeler.You can add entities to the domain model, create and edit pages etc.