I remember in Google Ads, we’d build all these cool looking dashboards but whenever we did user research it was pretty apparent that all they wanted was their data in a pivot table…
All these cool-looking dashboards are just too inflexible. You cannot add your own aggragates beyond trivialities. You cannot just "color that one value that bugs you". You cannot just generate a readable report plus some explanatory text.

Spreadsheet export + pivot table gives you all that. Doable for any moderately competent office drone without a round-trip through some endless backlog-spec-sprint-program-test-respec-sprint-... loop

To be somewhat constructive: What you rather should have done is not create more elaborate dashboards. What imho the world needs is an easy way to use a spreadsheet tool to generate and publish a dashboard. A "make web dashboard" button right next to the print button. With auto-updates when input data changes of course.
Yup. That's what I want to build. Thank you for saying that -- I feel like it really validates my feelings hah
The problem is always this project turns into “let’s build excel or tableau” and the customers that care usually already use one or the other.
That's fair, but fortunately I'm not planning on doing either. (Well, I am still implementing ~all of Excel's formulas for compatibility, but not the the UI/UX...)

People don't really consume data, they read documents. I think that's (part of) the vision these projects lack.

I'm working on an OSS BI tool focused on a document form factor. Might be of interest to you. https://github.com/evidence-dev/evidence