Maybe it is, would we've lived in a world of standards being developed, implemented and followed and users having good understanding about their computer system

Maybe it is, would we've lived in a world of standards being developed, implemented and followed and users having good understanding about their computer systems and networking concepts. Have you ever saw HLS or DASH HTTPS traffic tagged distinctively from bulk .iso downloads, and all that being distinct from page loads? Does your VoIP client uses DSCP field? Which level does it set? What ISP is to make if some "smart" client marks all their traffic as "critical"? And more importantly - how that's supposed to even work across multiple ASes? Heuristics is the only way it can be made work in the real world scenarios. That, or "sorry, we understand that your MMORPG lags terribly since the last week but we can't even try to help you" ISP support replies.