Agree but slight modification - goal should always be for the users to be able to do their main functional tasks in-application and maintain it as the system of record.
But there will always be a use for Excel as a tool for informal data-monkeying and analysis - exporting a table and doing some pivots to summarize or use a different view. Non-technical users will always expect this capability and flock back to it. Not everyone's a programmer or has the interest to be - you'll have to pry excel out of most accountant's cold, dead hands for example
You describe the ideal world. Tools like SAP or Business Warehouse suck at data crunching and nor everyone can use Python for example. Even ops can under the right circumstances be okish offline in Excel as long as results are imported into e.g. SAP to assure data integrity.
And then there are examples like the production planning done in Excel because SAP PP isn't just good enough. Then the guy who created said Excel tool left. Years later when production had to switch to weekend shifts zhey couldn't because no one could adopt the Excel tool. Once you reach that point you are screwed.