Well, I didn't count before giving you those numbers. I gave you my feelings, which were way high. It's 1 second for Pages. Libre is too inconsistent to give a number.

It's the story of open-source on Mac. Projects will have an anemic userbase. After all, most Mac users wouldn't be caught dead with Temu MS Word. This means the apps have very poor performance on Mac. No one is filling bug reports.

I think it depends if you preload libreoffice at boot time or not. It makes sense if you are using it daily, not so much if you are using it once every other full moon.