We have OnlyOffice as an alternative today. Personally I find the UI quite pleasing. But lately I haven't had any need to use office suite at home so I don't really use it so I have yet to find anything to complain (meanwhile, LibreOffice was horrible, while Office 365 was bearable until you stuff too many things in the equation editor).

Its really not that bad. I used to use it at work all the time. I did word processing, spreadsheets and presentations all the time with it. Maybe not as powerful as Excel, but I was never really a power user. But then again I never saw any spreadsheets that anybody used that were particularly complex.

At this point, LibreOffice is much better than whatever Microsoft now sells as an office suite.