> I made a passionate case...

There's a lot of good research and writing on this topic. This paper, in particular has been really helpful for my cause: https://dl.acm.org/doi/pdf/10.1145/3593856.3595909

It has a lot going for it: 1) it's from Google, 2) it's easy to read and digest, 3) it makes a really clear case for monoliths.