Is there still not any way to open Excel from an Office.js Word add-in and perform actions in Excel?
I found a similar question from 2020 here: Creating Word document from Excel Add-In with Office.js. The answer was "no" then, but I was hoping maybe things had changed.
Thanks!
No. Office Js seems designed for web use, where each document is independent. You can create but can’t manipulate an Excel document from within Excel, let alone from within Word.
COM Addins remain the most useful extensibility option for many, many use cases.