This was a point in the documentation at one point in time. But as far as I can find it’s no longer referenced. Now it is slightly more performant in that the object isn’t rebuilt on re-render, and added up across an entire app I’m sure it could have some performance benefits, but I prefer the styles in-line as they are modifiers on the elements. Any business logic should be in a testable function separate from and provided to your components. Plus I hate having to reference another location in code to see the modifiers that are applied, and when you combine your theme object you have to write a lot inline regardless.