system
Given the following post, respond as if you're commenting on Reddit:
human
What is physically different inside monitors that support 60hz vs 144hz?
gpt
The fundamental limitation as to how fast LCD panels can refresh is the motion of the liquid crystals.  Nematic liquid crystals are rod-like with an electric dipole and so the rods can be oriented by applying an external electric field.  The liquid crystal cells that form the pixels on the screen have grooves in them that tend to orient the liquid crystal molecule rods in one direction if no electric field is applied.  Once the electric field is applied, the liquid crystal cells rotate and align their rod axis along the electric field direction, which takes on the order of hundreds of microseconds to a few milliseconds.  This takes some time because of the viscosity of the liquid itself.  Once the electric field is removed, the liquid crystals realign along the grooves again but this also takes time, again on the order of hundreds of microseconds to a few milliseconds.  There are many proprietary techniques to speed this process along but this is the basic idea.  The electronics can handle, in principle, receiving pixel data from a video source and outputting a signal to the digital-to-analog converter at much higher speed than the liquid crystals can respond.  There are also effects from the matrix that addresses the crystals but the main limitation is generally the liquid crystal motion.

Lower refresh rates such as 60 Hz are really more of a legacy artifact of earlier video standards such as PAL (50 Hz) and NTSC (60 Hz) which were used for analog CRT-based televisions up until about 20 years ago.  If there was a few Hz difference between the line frequency that power was delivered and the refresh rate of the screen, it might cause flickering in the display that would be quite annoying, especially when the television standards were new in the 1930s-1950s and based on valve technology and tube rectifiers, and therefore it was decided to transmit the video signal at a rate very close or at the oscillation frequency at which power was delivered.  Being that CRTs are no longer used and power supplies basically pass basically zero ripple from the power line to the DC output used for modern televisions, this is not really a consideration anymore, and more just a legacy of adapting existing video standards such as 480i (NTSC) or 576i (PAL) to be usable on modern televisions.  It is likely that if broadcast formats did not have to be compatible with earlier forms of analog and digital modulation, higher refresh rates could be standardized, and dogs would be less annoyed watching TV with you.