Don't get me wrong, I use LibreOffice a lot, but I kind of despise it. The biggest headache I have, with Writer - which is what I use most often - is that if I select text in order to change the formatting, it changes formatting of stuff not selected. I think this has to do with paragraph styling .. it's just very unintuitive how it figures out what belongs to a paragraph or not. My human brain wants to separate paragraphs with line breaks. So why would formatting selected text on one line change the styling on adjacent lines that aren't selected?! It is extremely infuriating how its styling behaves in general.
I think it's also worth noting that rich text formatting is the primary reason to even use a word processor instead of a plain text editor in the first place. Embedded objects and exporting tools are all useful too. But most of what I use Writer for could be done in a text editor if I didn't need styling. So all these years later, a core feature - arguably THE core feature that necessitates the existence of the application to begin with - is still broken and unintuitive.
And when I search for help on how to get styling things working etc. and I find posts by other people that share these concerns, the answers are legacy document formats etc. that contain these bugs by design so it's something that's really hard for the developers to fix.