And this is what my yearly-or-so foray into Windows shows up - most apps look like garbage. The handling of displays with different DPIs connected to one machine is even worse. This has even been a solved problem _on Linux_ for quite some time.
Third-party apps, on the other hand, do seem rife with clipped text, even in English at nonstandard DPIs.
Edit: Ah, this was already said by the existing sibling comment.
Chinese/Korean rendered incorrectly on English UI because system hardcoded a font fallback, which put Japanese font first, regardless of how languages are ordered in the Settings. This is largely true for traditional Win32 programmes, like Chrome, Edge, Explorer.exe, etc. However UWP apps using the new UI framework (like Unigram, Intel Command Centre etc) behave correctly if setting Chinese/Korean as secondary language.
It's different on macOS or iOS however, if you set a system locale order as 1. English, 2. Chinese, then Chinese content will render correctly with correct Chinese system font PingFang.
Another issue that is also very important is that Chinese (Simplified or Traditional), Korean and Japanese share amount of the same characters but written differently. That means system must render the glyph in correct variant, like in the example of Source Han Sans
https://github.com/adobe-fonts/source-han-sans/raw/release/S...
This is big problem on Windows, where the heavy-handed hinting means actual font size doesn't even come close to being linearly related to requested font size. So you can't even make the simple assumptions such as that the same UI layout will work if you render everything at 2x for a high DPI screen.