Up until now, monorepo tooling in the wild has still been lacking. It remains a $BIG_TECH-exclusive technology. If you talk to anybody who worked there, they will tell you how superior that setup is. The more avid users will also tell you why it is better.

It is because dedicated teams work full time to keep a single repository healthy.

I mean, thats not a mono-repo positive. That's a "tech company pays to support it's internal tech debt" positive.

Mono repo's might be better, but the reasons given don't really inform.