This is why Google Sheets should be taking over the world. API-accessible, Javascript-scriptable, nice collaboration features. How are they not beating Excel online?
Google Sheets are surprisingly bad on phone. I wanted to "just" do drag-to-fill (or whatever is the name... that + thing that appears when you go to bottom right)... I could not do that on iOS Google Sheets?
And in general, Google Sheets on mobile are surprisingly poor.
Personally I feel like going in to JS/G apps script is actually a big bonus as it means you avoid some of the really gross stuff that you get in excel (which ime ends up being really hard to maintain).
I haven't used Google Sheets yet, but looks like I could just use their API and use a simple PIP package?