Well, you can have several Devolos in the power grid. Then the power is distributed. And the power grid probably produces many errors in the signal, so that data packets have to be sent several times. That's why the higher speed makes sense. I have also replaced the 500 with Magic 1. It works fine. However, one point to bear in mind is the power-saving mode. When it is active, it can take up to a minute for the signal to flow. I have deactivated it where devices need to be connected quickly.
I replaced the old Devolo 500 connection with the Devolo Magic 1 mini Starter Kit because the loss was very high depending on the line. The new connection runs much better and is very stable. My conclusion: More reserve equals better transmission, or less loss.