It was that way for years, but at some point recently they finally seem to have fixed it - I can now enter the start, end, or just part of anything I want to find, and it finds it! You know, the bare minimum you'd expect from a search function!
I'm actually a big fan of Windows 10, but it boggles the mind how long they left such a key part of the Windows experience in such a sorry state.
It's absurd that Apple came up with Spotlight in 10.4 (15 years ago) and Microsoft still hasn't caught up with such a fundamental game changer.
There's an issue open here about this:
It's kind of crazy to think back to those conversations with Microsoft about their long-range plans. Some they have delivered well, like the transition to a subscription model for client applications. Some they have not, like native peer-to-peer social networking in the OS.