You're right, but even many builtin Microsoft apps - while they supported DPI scaling - did not support multi-DPI switching and rather than scaling properly just scaled pixels and looked blurry.
It's "not Windows fault", sure but it certainly makes it a worse experience than other platforms like OSX where multi-DPI is much more commonly supported.
I would much prefer the Windows behavior to what I see on Linux. Right now, if I open an app that doesn't support high DPI, it is just unusable because it is so tiny.
It's "not Windows fault", sure but it certainly makes it a worse experience than other platforms like OSX where multi-DPI is much more commonly supported.