I'm kind of surprised why this is even relevant to you. The designers I know work in Figma. The designer and the engineer collaborate to make sure the design is

I'm kind of surprised why this is even relevant to you. The designers I know work in Figma. The designer and the engineer collaborate to make sure the design isn't too hard to implement, but other than that the designer shouldn't care about whether developers are using Tailwind, StyleX, Sass, vanilla, or whatever. I hardly expect a designer to take responsibility for something as transient and idiosyncratic as "oh, but this is hard in Tailwind."