Even more ridiculous since a 1.4x performance increase is already incredible news for anyone who makes regular of this.
If someone found a software optimization that improved, say, blender performance by 1.4x people would be shouting praises from the rooftops.
This sounds more like the infrastructure in your area just isn’t up to delivering those speeds, regardless what the last mile to the home is.
I promise you Steam’s CDN absolutely can deliver more than 450Mbps. It regularly maxes out my 1.5 Gbps at home, and I have no doubt that it could potentially go even faster than that if I had a better connection.
Like plugging a 10Gbps network switch into a 100Mbps gateway, it sounds like a fast final link to the home is being choked out by poor infrastructure in the region and can’t be fully utilized.