Comment by adrian_b

These might depend on some options chosen by whatever Linux distribution you have used.

As always, the behavior seen on some Linux distribution for some application may not match at all the experience on other distributions.

I always compile LibreOffice from sources (in Gentoo) and I have not noticed any performance problems, and most of my text documents or spreadsheets are quite large. It is true that currently I use it only on decent computers, but in the past I have used it even on several generations of Atom CPUs, from Pineview to Gemini Lake. Even on those there were no performance problems, at least not with Writer and Calc.