For many decades, there have existed commercial apps native to the Apple ecosystem, often from small/mid-sized studios, which would use native UI to signal their premium craftsmanship. I think that for many long-time Mac users, seamless/native UI is still a signal of quality in third-party software. However, this sentiment is moribund. That entire market is now dwarfed by the ecosystem of “cross-platform apps” (formerly Windows ports, now usually web apps) and Unixy OSS tools; all the while the Mac App Store now peddles lots of native-UI apps of deeply questionable quality.