I'm legitimately asking because I'm curious, not trying to start a flame war here...
What features are you missing in LibreOffice Calc that you use in Excel? I personally use Calc at home, but can't get away with it a work because of imaginary numbers. (Although most things I've just moved to using Python + Pandas because both programs can't handle large datasets very well)
Power query/pivot, 365 integration, stat/finance functions, forecasting models, VBA, etc.
Mainly because I use Excel for work. I don't want to hack together a solution in the middle of my workflow with Python and other FOSS tools. I need it to just work. And Excel just works.
I absolutely love Libre/FOSS, but I don't always have time to fuck around learning new ways to skin a cat. I'll almost always recommend proprietary solutions if that's what you're used to. It just makes sense. 🤷♂️
Always use the tool that's best for the job, and sometimes that's hot steaming piles of closed source shit.