I have been using tailwind on a new project and I only see 3 real benefits over using inline css styles:
1) Sizes are standardized in a predetermined set of discrete size classes. So you start to think about sizes, padding, margins, etc in terms of steps instead of values. You can change the steps in one place and they apply globally. It's a little easier to standardize a rough style guide compared to starting from scratch.
2) Colors are standardized in a similar way. You just need to configure your app's core colors and then you can just think in terms of steps instead of color values.
3) You have a smaller set of "best practice" means to achieve most outcomes compared to all that's available with css. You don't need to know the best way to do what you want, you can just browse the documentation to find what you want.
Outside of that, you still have to use @apply to collapse utility classes into more semantic classes if you want style changes to cascade (tailwind recommends using components or view partials to achieve this instead of via css classes, though this would work equally well with inline styles)
The styles are very verbose, just like with inline styles. They are only slightly shorter than inline styles since they are basically abbreviated forms of inline styles.
You can still do everything tailwind does for you by using your own style guide and building out css classes, but tailwind gives you a head start.
It feels like it makes you more productive in the beginning because you get a toolset with a lot of decisions already made for you, but I suspect it will make things a bit slower as the app gets more complicated.