AFAIK normal wired internet in household is on best effort basis and same line is shared for all connections in the apartment. I doubt speed is guaranteed there. Normally for guaranteed bandwidth, up-time etc one need to use leased line.

Once upon a time I just used basic cable connection(2 Mbps) which was included in the rental agreement. It wasn't fast but Youtube 480p videos played without buffering. Now I have 10 Gbps fiber connection but no device which could achieve more than 1 Gbps.