My problem with LibreOffice and the other open source versions of Office is the outright thievery involved. I'm sure MS didn't spend millions (billions?) on developing Office over the years just for a bunch of basement coders to rip off their IP and build an exact copy.
"Open source" means anyone can look at the code. If Microsoft saw ripped-off code, they'd do what most companies do: sue like hell. That's true of all open source. LibreOffice's macro language isn't VBA because they don't have a license for it; LibreOffice often can't even convert VBA to its own macro language without loss, and the help community recommends just starting over. The fact that LibreOffice etc has similar functionality and appearance is meaningless: all word processors have to do pretty much the same thing, and if they want to stay competitive they'll try to keep up with new features. They also want to make switching fairly easy, which is aided by similar appearance. (LibreOffice actually defaults to a different appearance, and you have to find the option for ribbons if you want that.)
Incidentally, sometimes companies release their proprietary code into open source. Sun Microsystems owned the suite StarOffice, which they made open source, and that became the basis of several successors, including LibreOffice. Likewise, Google made the basic browser engine behind Chrome open source in the form of Chromium, which numerous browsers now use (including Microsoft's Edge). That's another situation in which similarity doesn't mean theft.
In short, your accusation of theft is simply false.
I'm not particularly eager to change from MS 365, but like the other people in this thread, I'm very frustrated by MS's implementation of OneDrive and now the coming increased subscription fee. So I'm examining options.