Could you please link to some official sources to corroborate these claims? I'm not trying to suggest that what you've said is incorrect, and in fact most of what you've said is likely true given the premise (architectural decisions like using udp instead of TCP, and peer-to-peer networking) is actually true.
I know quite a few peeps who red bar in Destiny (which you suggest is packet loss on their side) but play games like WOW, CS GO Battlefield and Overwatch perfectly fine. Based on my knowledge (background in network engineering) and experience with Destiny - I have always assumed that the upload speed requirements of Destiny, due to its peer-to-peer design, has a heavy burden on upload bandwidth. And, given that in Australia most people do not have upload bandwidths above 1mbps - this would produce significant packet loss due to a congested up-link.
Now, in a way that is exactly what you've described, but I don't think using UDP is the primary cause - although it certainly doesn't help (or does it? imagine if the packets had to be re-transmitted (TCP) ... gahhhhhhh). The root-cause is likely the result of too much information being transferred between p2p nodes.
I'm fairly certain that games like CS GO (client-service architecture) utilize UDP for game traffic.