In a modern household you may have multiple people on the same connection. Two people streaming Netflix at 4k from the same household would not work in your exa

In a modern household you may have multiple people on the same connection. Two people streaming Netflix at 4k from the same household would not work in your example of "sufficient" 25mbit/s speeds. Additionally, higher speed provides opportunities which lower speeds don't (e.g. building a live streaming business) which you otherwise don't have.