I’m an accountant. I use Libreoffice to write complex written documents and manage reasonably large data sets for 40 hours a week for the last decade, and openoffice before that. I encourage my small team to do the same and for the most part, they do. We all have both libreoffice and microsoft suites on our desktops. It’s fine. I feel like it’s the humble workhorse that has served me very well for many years with no fuss. I’m sure someone will be along in a moment to tell us all about how any serious professional uses excel. There always is in these threads. For my own part I feel like LibreOffice is one of the great success stories of open source.