Because it works exactly for the thing it was designed to do, and does it well. Like asking why we still use hammers to pound nails in after a thousand years. Some things are going to stick around for a long while and not just go away because “progress”. I fully expect some form of Ethernet to still be used 50-100 years from now just like analog phone lines are still used now, and those are over 100 years old.
Because it works exactly for the thing it was designed to do, and does it well. Like asking why we still use hammers to pound nails in after a thousand years. Some things are going to stick around for a long while and not just go away because “progress”. I fully expect some form of Ethernet to still be used 50-100 years from now just like analog phone lines are still used now, and those are over 100 years old.