Decades of being the standard in a/v. That’s like asking, why don’t we get rid of gas stations and just install electric chargers? Well, everybody’s got gas powered cars.
AV things sure since they stick around longer, but computers? When was the last time you saw a high end GPU with VGA or DVI? And they already usually have mostly DisplayPort with just one or two HDMI ports
Well, I wasn’t referring to that ecosystem. That ecosystem is already on display port. The reason HDMI is so prevalent is because it’s the standard in audio-visual equipment. Why would I talk about computer equipment when it’s not the standard there?