> Is there a reason the latest chrome can't run on 7 if it didn't check for it?
The reason is precisely because it doesn't check for it.
That is: instead of checking for older Windows releases, and using fallback code paths for them, it simply assumes the presence of newer APIs (or that older buggy APIs now work properly). As time goes by, the cost of maintaining these fallback code paths only increases (and in some cases, having to stay compatible with them prevents important enhancements and cleanups), and since they're less tested (because they're only used when running on older operating system releases), they tend to break. As an example from an unrelated project, before they dropped Windows XP support, the fallback code for panic!() in Rust was broken when running on Windows XP (https://github.com/rust-lang/rust/issues/34538).
The reason is precisely because it doesn't check for it.
That is: instead of checking for older Windows releases, and using fallback code paths for them, it simply assumes the presence of newer APIs (or that older buggy APIs now work properly). As time goes by, the cost of maintaining these fallback code paths only increases (and in some cases, having to stay compatible with them prevents important enhancements and cleanups), and since they're less tested (because they're only used when running on older operating system releases), they tend to break. As an example from an unrelated project, before they dropped Windows XP support, the fallback code for panic!() in Rust was broken when running on Windows XP (https://github.com/rust-lang/rust/issues/34538).