I've never had a problem using LibreOffice or OpenOffice to replace Word/GSuite. I've had some compatibility issues to open PowerPoint files, but that was usual

I've never had a problem using LibreOffice or OpenOffice to replace Word/GSuite. I've had some compatibility issues to open PowerPoint files, but that was usually limited to editing them. Creating presentations in LibreOffice or OpenOffice was harder than GSuite or PowerPoint as well, precisely because the latter two treated me more like I was an idiot and I'm not good at designing slides. To be clear, as your edit says, your CFO and other modellers are probably going to have to use Excel. There are just things that work in Excel and nowhere else.