And it isn't because they didn't try Sheets. Lol. Nobody I know likes Google Sheets.
They basically copied the UX of Office 2003 and did nothing to improve upon it since it's initial release over a decade ago.
It's awful.
Shit, it still doesn't have the concept of tables like Excel does and you need to manually paint rows, manually find the hidden filter creation option for cells and manually refresh the table because the fitlers are kludged such that they don't automatically re-filter when you edit a row.
Even Mail Merging is awful. https://developers.google.com/apps-script/samples/automation...
Like, you don't need a programming degree to mail merge in Office but you do for Google Sheets because it's a script instead of built-in feature.