In my experience the article is right when it tells you there isn’t that big of a difference. We have all sorts of repositories, some of which are basically mono-repositories for their business domain. We tend to separate where it “makes sense” which for us means that it’s when what we put into repositories is completely separate from everything else. We used to have a lot of micro-repositories and it wasn’t that different to be honest. We grouped more of them together to make it easier for us to be DORA compliant in terms of the bureaucracy it adds to your documentation burden. Technically I hardly notice.
The basic way most work is to run full CI on every change. This quickly becomes a huge speedbump to deployment velocity until a solution for "only run what is affected" is found.