This might be a dumb question but is there a possibility to
define models/schema to a page-like structure? I was thinking
if it’s possible for a user to not touch the models so when creating new pages
it will just be in the content section. Another thing would be to define nested pages.
If that is not enough, you can still keep the tree-like structure to create pages and then instead of having the modular content you link to other models where you can define all the different templates that you have implemented.
You can leave the root element without blocks, but it will have the modular content field, which will be empty.
But all the records of an item type must have the same schema. If you want to prevent your editors to write in the root element you might build a plugin that hides the field if the record is top level maybe?