This is an incomplete take. People use MS Office because everyone else uses it. In practice, that means if you try an alternative, then there's no assurance that your documents will render or function the same way on an MS Office installation.
I tried going all LibreOffice when I was a grad student. I had to write a tech report to submit to our funding agency, using a Word template they require. It looked great on my computer. But when my advisor reviewed my document on his MS Office installation, the formatting was all wrong and unusable. Ditto for spreadsheets and slide decks (I can't count the number of times Google Slides mangled my PPTX formatting after I accidentally opened the file in the browser and it auto-saved). That's the reality of doing non-trivial work with external stakeholders if you're not using MS Office.
How long ago was this?
It doesn't work when you're required to submit MS Office documents to people who pay you. You can't tell them "LibreOffice is so great, you should use it too!" You either use MS Office, or you look like a sloppy amateur when your figures are the wrong size and the text is overflowing off the side of the document.
One time we were having a hard time exporting Word docs that a customer was able to open and view correctly. After much back and forth, it turned out they were also using OpenOffice and it was having trouble opening the emulated Word docs we sent. We cut out the middle man and started sending them OOo’s own native docs. Problem solved!
I know that’s far from the common case, but it made me so happy at the time.
Microsoft office supports ODT these days... you can tell them to "just open it in Office" and it will work.
Also, the LibreOffice DOCX export filter is pretty good. Not perfect, but then, if you need that perfection, why not submit a PDF?
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And finally: To help LibreOffice (and its filters) improve, we need to contribute either money or development time: www.libreoffice.org/donate
And saving as a pdf is a fine compromise when the receiver doesn't have a need to edit the document.
Though to be fair, I didn't really have a choice in the matter. its was that or the web version of office.
I feel exactly the same way about that. And I often use it for stuff I don't need to collaborate on. But for paid jobs with stuff I need to round-trip with people who I know are using Microsoft products, I just use the Microsoft products myself.
It's cheap insurance against giving the people who are paying me to collaborate with them a bad experience.
I can invite people in with SSO so they do not need to make yet another account.
I would give anything for a standalone, offline spreadsheet software as robust and powerful as Excel. Unfortunately, that doesn't exist.
It works, but its clunky, you have font shenanigans, it just overall feels weird and not smooth...
Then again, I'm one of the people who would force you to pry Office 2003 (the last version before the ribbon) out of my cold, dead hands.