One example is rotation along axes other than Z, which is required for 3D transforms. Here's a two year old issue on it: https://github.com/tailwindlabs/tailwindcss/discussions/3521

Another is attribute selector support. They have many common ones, but to do anything more complex you need to add support to your configuration. https://tailwindcss.com/docs/hover-focus-and-other-states#at...

I don't want to oversell this; I think Tailwind does a pretty good job covering the "happy path", and if you haven't run into any gaps I wouldn't worry about it too much. But you'll encounter its limits well before you encounter the limits of CSS.