That seems more like an entrenched opinion that you've continually looked to reaffirm instead of opening your perspective.
First, serious work & powerpoint? Really? Yeah in an enterprise organization that's largely stuck doing what they've been doing because it's worked - sure, but that's not a technology issue, it's a culture issue.
For example, Google Sheets covers 80-90% of the use cases for Excel. But that's not what you should be comparing. A lot of what folks use spreadsheets for to do complicated calculations, have built lengthy, stitched together macros to automate processes, etc. would be much better in many cases to consider a completely alternate approach.
i.e a data warehouse, hey use a service like BigQuery that requires minimal adminstration and requires users to really only have SQL knowledge.
In order to effectively work across a large organization across different functions, product lines, etc., you have to remove every point of friction that prevents collaboration, etc. Desktop Office is great for individual work, but in today's dynamics, it really seems like you put a ceiling on productivity by sticking to it.