Please consider taking network speed into account. The device can be great but on mobile network it may take ages to load everything, depending on the location (e.g. on a train you may not have stable 5G long enough).

This is still a consideration, and one of the reasons that having a customized server delivery is an important capability.

Responsive sites still upload the same data, but show less of it to you.

That said, if there were a way to report network connection speed to the server, it could make the decision to reduce the data load (regardless of end device).