You don't seem to understand how sensitive voice traffic is, so I'd suggest you do a little reading.
You said: "A packet lost is an interruption in voice."
Your link says: "Some degree of packet loss won't be noticeable"
ie. You're not a VoIP engineer.
The large file traffic now completely stomps on the VoIP traffic, causing packet loss and delivery delays.
Except it doesn't, because none of the internet protocols are one-way broadcasts. Controlling the ACKs sent out directly controls the speed of incoming traffic. NO network admins responsible for a network larger than 10 people would make a stupid ignorant mistakes like this. Weighted fair queuing is CCNA-level network bare-bones network admin basics. A network won't even be USABLE for two people at the same time if proper queuing isn't enabled.
ie. You're not even a network engineer.
If QoS worked on the Internet, we'd all mark our traffic with the highest priority AND THEN QOS WOULDNT WORK ON THE INTERNET.
This isn't even a coherent thought. Replace "internet" with "MPLS" and it would still work just fine.
Tagging isn't QoS. You don't NEED QoS "on the internet" as the backbone is fast. You need QoS on the bottleneck, which is always your uplink, and your network admin (which you are not) controls the queues and hence QoS on those.
2) Doesn't understand the need for inbound QoS
You've made it clear you don't even understand what QoS or queuing IS or DOES. Having my knowledge insulted by you is practically a compliment at this point.
Your comments in this thread are one of the best examples I've even seen of the old adage:
"It is better to keep your mouth closed and let people think you are a fool, than to open it and remove all doubt."