I've tried using a 43" UHD TV as a monitor, since they're as cheap as $149.99 USD brand new, but it had noticeable delay even at 4k@60Hz, and just didn't feel right.
This is typically due to default settings on TVs enabling various high-latency post-processing options.
Most TVs have "game mode" settings that disable all these at once, at which point latency is comparable to monitors.
Case in point: at both 60 Hz and 120 Hz*, 4K latency on my LG C4 is within a millisecond of the lowest-latency monitors listed here:
I fully agree that HDMI is inferior to USB-C, if only because quality USB-C-to-HDMI adapters are widely available, and mini/micro HDMI connectors commonly used on small devices (not including this laptop) are garbage.
* Probably also true at 144 Hz, but the linked table doesn't have a dedicated column for 144 Hz, complicating comparisons.
This is typically due to default settings on TVs enabling various high-latency post-processing options.
Most TVs have "game mode" settings that disable all these at once, at which point latency is comparable to monitors.
Case in point: at both 60 Hz and 120 Hz*, 4K latency on my LG C4 is within a millisecond of the lowest-latency monitors listed here:
https://www.rtings.com/monitor/tests/inputs/input-lag
I fully agree that HDMI is inferior to USB-C, if only because quality USB-C-to-HDMI adapters are widely available, and mini/micro HDMI connectors commonly used on small devices (not including this laptop) are garbage.
* Probably also true at 144 Hz, but the linked table doesn't have a dedicated column for 144 Hz, complicating comparisons.