There was a panasonic (I think it was them) that had a Displayport connection, but that didn't last.

I suspect HDMI threatened to cut their licence if they kept putting DP on the TVs.

TVs are not very good displays for computers. You have to go through a bunch of settings to turn off as much image processing as possible. Even then, the latency will still be higher than a gaming monitor. You have to disable overscan, which always seems to be on by default even though it's only useful for CRTs and makes absolutely no sense for a digital display with digital signals. Also, I've never had a single TV that will actually go into standby when commanded. It will just stay on with a no signal message when the computer turns off the output.

DisplayPort is designed to give your GPU a fast connection to your display. HDMI is designed to give the copyright holder of the video you are watching a DRM protected connection to your display to make piracy harder.

This is why DisplayPort is better for the consumer but HDMI is more popular because the device manufacturers are really in charge of what you get.

Aside from DisplayPort having more bandwidth, as someone else pointed out, HDMI is consumer video garbage. DisplayPort was designed for use as a computer display. Also, HDMI Forum is a cartel that charges ridiculous licensing fees for their proprietary interface. VESA is a standards body and their licensing costs are much more reasonable.

HDMI 1.4 has a less than half the bitrate of the oldest DisplayPort standard. And regarding the newer HDMI standard: read the article. The forum are being jerks...

The only disadvantage of display port that I can think of is that it's harder to find capture devices (or at least Linux compatible ones) that have display port. Generally no one cares about that stuff though. I use capture cards because I sometimes do stuff involving other computers and it's 1000 times more convenient to have a vlc window floating around with the display output.

No one seems to have this use case besides me, I'm just glad that there exist capture cards fast enough to do playback in real-time and not a 5 second delay. I don't stream.

Me neither. I play at 1440p/120hz. Both cables can manage that resolution and frame rate.

The only difference I get is when I use DisplayPort and leave my computer alone for 20 mins, the GPU goes to sleep and the monitor won't display anything although I hear background apps/games running.

Without changing any settings, using a HDMI cable solved that.

HDMI it is.