Outside of the ones built into laptops, all my "monitors" for the last decade have been TVs, just because they tend to be cheaper at a "price to size" level.
Yeah TVs typically don't have DP, because extra HDMI ports are usually more valuable in a home theater setting. Game consoles, receivers, video players all have HDMI and don't have DisplayPort, meanwhile every graphics card and laptop usually supports both, so having an extra HDMI port ends up being more versatile.
There is supposed to be some sort of conspiracy where the HDMI consortium actively tries to keep display port off of TV's.
Not sure if I buy it, how would that even work? lower licensing fees when no display port? I suspect the real answer is that HDMI managed to capture the market for digital video links and while display port is better it is not enough better for people to want to make the incompatibility jump.
But.... Conversely it does almost make sense. because finding DP on a TV is super rare, nobody is even trying. Historically you would find all sorts of rareish connectors on TV's(component video, s-video) so.. conspiracy... perhaps.
None of them ever seem to have DisplayPort.