May I ask for a few examples of things you do in Excel that don't have a replacement?
The vast majority of people I have seen using Excel don't know how to write a formula. Now they just started copy-pasting whatever ChatGPT was telling them to copy-paste, but well... and anyway all the alternatives do support formulas of course.
It's been years since I've really tried to exercise Excel (and haven't used it--or Libre Office--in a long time). Pivot tables, a number of the other data-related functions... Just a bunch of things I'm not going to spend a couple of days digging into. Google Workspace works fine for my needs.
There are plenty of functional replacements. However there are zero replacements that emulate the same keystrokes and keyboard shortcuts and all other aspects of hard-won muscle memory like function names and quirks of behavior.