I don't think it's quite that simple. DP is still missing HDMI features like ARC and CEC, which are important for TVs. Even on my personal computer setup, I use the HDMI 2.1 ports on my monitor/GPU over the DP 1.4 ports because the DP port just doesn't have the bandwidth for 2560x1440 @ 240hz with 10-bit colour. That requires ~30 Gbit/s, more than DP1.4's ~26 Gbit/s.
Neither my monitor nor my GPU support DP2.0 which does have enough bandwidth. So until I upgrade both, I'm using HDMI. My computer is not outdated either, there's just nothing to upgrade to. None of Nvidia's consumer GPUs support DP2.0, and I can only find 2 monitors that support DP2.0. Anyone getting new hardware now will be in a similar situation to use HDMI2.1 over DP1.4 until their next upgrade.
Neither my monitor nor my GPU support DP2.0 which does have enough bandwidth. So until I upgrade both, I'm using HDMI. My computer is not outdated either, there's just nothing to upgrade to. None of Nvidia's consumer GPUs support DP2.0, and I can only find 2 monitors that support DP2.0. Anyone getting new hardware now will be in a similar situation to use HDMI2.1 over DP1.4 until their next upgrade.