I’ve been marinating in the world of Swing for about 17 years now, and one thing that I will say for certain is that trying to achieve native fidelity (not even the feel, but just the look of components) is a herculean task that requires constant work.

Swing engineers tried to do that at some point by delegating all the rendering to native APIs. That worked to some extent. But not the animations – since these controls were not native ones. And over the years the gap between the visuals of Swing controls under that cobbled-together house of cards and the real native controls keeps on growing larger and larger, as Microsoft keeps on tweaking and changing what native look and feel is.

The same goes for macOS – every release changes things for individual controls, as well as the overall structure of the window and the content in it. Even if somehow you managed to get aligned with the absolute latest macOS visuals (including light/dark and accent automatically respecting the user setting), if you don’t do a window layout that matches the platform guidelines, you’re still off.

And again, every year, every major platform changes things. So whoever it is that provides the UI kit that aims for native fidelity, needs to make a hard decision. Do they follow the latest native look and keep on switching to the latest native APIs (effectively abandoning the older versions of those platforms), or do they create a monstrosity of backwards compatibility, that eventually requires so much testing and hand-holding, that it collapses under its own weight?

And of course, the moment that person / organization stop maintaining that library is the moment it simply stops working on new versions of those major desktop OSes. That’s a hard guarantee.

If anything, the beautiful thing about the web expansion in the last 6-8 years is that it has shown that the end users simply do not care about native fidelity en masse. Sure, there is a small, dedicated, vocal cohort of die-hard aficionados that are willing to die on that hill, but the 99.9999% of users do not care. They want to get their thing done, and move on.