It doesn’t matter if you have 2 Gigabit internet if no one in the world is uploading even half that fast. A single download on Steam is like 450 Mbps
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.
My partner was subscribed to Crave for ages. A little while back she was in the middle of a rewatch of Sons of Anarchy when the app started to act up and wouldn’t work, so I grabbed a copy and put it on Jellyfin.
She was floored by how much immediately better the video quality was and cancelled Crave the next day. Shocked at how much worse the experience was with the paid service compared to free.