What is a style? Are you trying to create a poster or do some graphic design? Some weird xml style sheet thing? Yes it’s not for that, but then also doing that in libre office or word also sounds horrible and unmaintainable.
That is, I should be able to define a "Code block" style that should appear in the same dropdown where google docs lets you select heading levels. When I select that "Code block" style, the app should format the selected bit of text according to the syte's definition. For instance: use a monospace typeface, apply some margins to this paragraph and paint a gray background on it.
Likewise, I should be able to update the style definition and all code blocks should update accordingly.
This is very basic functionality that has existed in word processors since... forever. Large and/or more complex documents are simply much much more painful to maintain/evolve without this feature.