One isn't better than the other — it all comes down to use case.
I have a Dell U2720Q monitor that accepts HDMI 2.0, DisplayPort 1.4 and USB-C. I use USB-C because the monitor acts as a hub for a range of peripherals (keyboard, mouse, webcam, speakers, etc.etc) and ...
There's a lot to consider when buying a gaming monitor these days, more so than ever before. There are the basics, like screen size, resolution, and refresh rate. But then you have adaptive sync ...
DisplayPort has a clear advantage over HDMI on paper, but most smart TVs you can buy these days still use HDMI. Here's why they're sticking with it.