Excel is really good for the wizards and for that one spreadsheet full of macros written by a wizard, which thus can't be ported over to Libreoffice or anything else. Many of those probably should Just™ be made into actual databases, but Excel is a lot more approachable than those, so you end up with giant spreadsheets instead.

For everybody else, Libreoffice is fine as far as functionality is concerned. UI might be another story, but that's worth getting over anyway, especially since a lot of people for whom this is a problem, would also have problems with getting away from Windows as a whole, just from buttons moving and things being different in general.

Porting involved Excel sheets into web apps has been a decent chunk of my dev career.