Both are needed.

The challenge right now is we need a summary view of where all our extension fields reside (our extensions are modular so our app is spread out across several extensions). Simple VS Code intellisense enhancements won't address this. What the AL Language Extension needs is a Field Viewer so when I open an .alpackages application symbol file in VS Code, it'll list all the fields present in that symbol. The application symbol viewer also needs an export to CSV feature (both for fields and objects). Another issue is that viewer can only view one application symbol .app file at a time. It would be helpful if there were a command pallete to show all objects from all downloaded symbols without opening up one .app at a time (our core extension depends on 20 other boilerplate extensions)

By augmenting VS Code enhancements with a new Virtual table in Business Central itself, we can do our own field analysis via reports and pages with the help of a virtual table. The problem with the virtual table approach is our extension needs to be published and installed for it to be useful (not helpful for fields still in the development pipeline). So adding this kind of visibility in both BC and VSC are equally important.