Are you in London? My 1Gbps link gives 800-900Mbps in these speed tests, and I'm fine with that. It's a pitty that some of that is unused because I need to use a VPN.
When I lived in a small town, my 500Mbps would give me >400Mbps consistently.
When I lived in a small town, my 500Mbps would give me >400Mbps consistently.