It's hard to quantify exactly but Google sheets has nowhere near 85% of the features of MS Excel. Maybe 40%? There's tremendous depth to Excel which most users never touch, but which some of us absolutely need.
The latest release of Excel seems to be fully caught up to Sheets on collaboration features. We can save a file on Teams and then have multiple users editing simultaneously through a mix of desktop, mobile, and web clients it works really well.
Interesting, I realized after reading your comment that I had mentally parsed the above comment as meaning "85% of users have every feature they need" (and presumably some non-zero but decreasing percentage of the features the others need), but looking back I see that's not how it's phrased. It does make me think more about how "40% of features" versus "85% of features" should be interpreted though. Even assuming that there's agreement on what counts as a single feature versus multiple related but separate features (which isn't a guarantee), should every feature be weighted equally? I could see it being more reasonable to weight features by how necessary they are or by how much they're used; is the ability to do something very basic that almost everyone needs like summing a range the same "percent" as something more esoteric (I'm not a spreadsheet power user myself so I'm not sure what would be a good example here, but maybe calculating a regression of some obscure function class)?
The latest release of Excel seems to be fully caught up to Sheets on collaboration features. We can save a file on Teams and then have multiple users editing simultaneously through a mix of desktop, mobile, and web clients it works really well.