Traceroute work by routers decrementing the ttl as the packet passes. If a router doesn’t decrement, or if your packet gets bundled into an mpls, the hops may be hidden.

Then you’ve got the buffers - you could feed 5x100M streams on 1G carriers into a 1G uplink port and have plenty of bandwidth, but if all the packets of those 100M streams arrive in 100ms, then have no packet for the next 900ms, your outbound traffic will have to either delay your packets upto 900ms, or drop them.