

Yes, LibreOffice uses its own custom rendering engine and that’s not the most performant…
But you have to understand that before LibreOffice there was OpenOffice.org, which itself comes from an old German application called StarOffice.
And oh boy, StarOffice! It was quite peculiar: it used to render its own desktop environment that took over Windows Explorer, with its own Start menu!
So, let’s all remember that LibreOffice still has that legacy to carry on.











And that pic is with the classic (Office 97-style) interface.
You can also switch to a more modern style, called “Notebook bar”, which is similar to the Ribbon interface you can find on Office 2007+.
(Honestly? In my opinion, the classic interface is the best)