This is my experience as a data engineer/analyst. I work in the healthcare space and my analyses are run on datasets that are at the uppermost half a million rows. Yes, data.table is faster than dplyr/tibbles, but i dont care. Like you said, most of my time is spent on expressing my thoughts into code, not running the code. Tidyverse really simplifies it compard to base R.

Its good to know tools like data.table exist though, people shouldnt think the tidyverse is the only way to do things.