Excel is distinctly different from the rest of Office for a power user because while you're right that they've reorganized things (though only one real reorganization since at least Office 95, that's pretty good), the keyboard shortcuts have remained the same for literally my entire life. It's why Excel is nonstandard and weird compared to even other Office apps: Excel is the most this-is-for-work tool in Office, and they've been loath to break things for people like...well...me.

And I don't hate the ribbon interface, I think it's totally fine--but also, in Excel specifically, I almost never click a button on it.

QuickBooks's online version, on the other hand, has terrible discoverability and doesn't have standard keyboard controls.