Why didn't HTTP/2 use a different URI prefix instead of complicating HTTP/2 with backward copatibility support or HTTP/1.x?

Why did HTTP/2 folks decide to re-use the URI prefix of HTTP/1.x (i.e. http://...) and --to distinguish the two protocols-- complicate HTTP/2 so that it handles baclward compability?

Wouldn't it be better if we just use a URI to do its job instead of complicating a protocol to do backward compatiblity fallback things?

Like, would it be nice if http://....etc uses HTTP/1.x, and http2://.... uses HTTP/2?

This way we won't NEED backward compatibility in HTTP/2. Instead, the browser can decide whether it should assume "http://" prefix or "http2://" prefix. Much better/cleaner separation if you ask me.