Out of order delivery is a complete red herring. Modern QoS systems don't cause packet re-ordering, though they do cause some re-transmits for flows that don't support ECN and thus need packet loss as a congestion signal. Video streaming like Netflix and YouTube has buffering far in excess of the RTT, so retransmissions don't hurt noticeably.

But you're still missing the main point, which is that good QoS doesn't need rules that single out and privilege or deprioritize any specific classes of traffic. Discrimination rulesets are obsolete. A network with good AQM at points of potential congestion will support full bandwidth utilization with sufficiently low latency for applications like VoIP and gaming, which can coexist alongside video streaming and bulk file transfers. QoS can be both effective and neutral with respect to content type and transport and destination.

Bad obsolete QoS shouldn't be used as an argument against net neutrality regulations. If it happens that net neutrality regulations both prohibit unfair business practices and require ISPs to fix broken congestion management, that's a good thing.