I would say it is more the lower entry barrier for devs who do not want to spend time on learning css so they are not that relient anymore on a dedicated frontend person
But Tailwind works for me because:
- it gives good defaults (from sizes and distances to color palettes)
- it's documentation is heavenly, and helps you find the precise thing you're looking for in seconds
I actually leveled up my understanding of CSS thanks to Tailwind :)