Yeah I don’t think the internet speed is the issue. It really only seems to matter when it’s “checking for updates”. You could turn off all data though and then reload the sim to see if that makes a difference.
I did hear someone complain that their load times became insane after they plugged in their new yoke. So perhaps as a diagnostic you could try unplug any USB devices other than keyboard/mouse.
Just to add, I have probably a 200-300GB install and yeah, it’s probably about a 3min load time. Something ain’t right.