The fact is that "monolith" applications can scale, and they can be deployed as a unit and they can still adjust to varying load using modern cloud infrastructure.
The enemy to scale, productivity and success isn't "monoliths". It's complexity! And an experienced and pragmatic developer will tell you that they fight daily to avoid complexity at every turn. Yes, sometimes it's necessary, but they weigh the pros and cons on a case-by-case basis to ensure that the gradient to complexity is always as low as possible.