The most notable benefit of a higher-end television right now is adaptive sync, often referred to by tradenames such as AMD FreeSync or Nvidia G-Sync.
These television sets like similar computer monitors can adjust to the variable output of a computer or videogame console's graphics output to prevent tearing.
Examples of tearing can be seen here:
and here:
How AMD's FreeSync and Nvidia's G-Sync adaptive sync (aka variable refresh rate) monitors improve PC gaming by eliminating stuttering, tearing, and ghosting.
www.pcworld.com
If you plan to game on the television set with one of the newly released consoles (Xbox or PS5) or with a Windows gaming PC in the near future, it would be wise to consider a television set with adaptive sync like the LG CX series (which starts around $1300 for the smallest 48" model). On TV sets, sometimes adaptive sync is listed as VRR (Variable Rate Refresh) in the list of features.
Other benefits of higher-end TVs might also include OLED panels (deeper blacks), HDR10 and support for modern standards like Dolby Vision and Dolby Atmos.
One thing that doesn't typically show up in a spec sheet are viewing angles. Inexpensive television sets have narrow viewing angles; better quality sets have wider viewing angles so more people can enjoy the high quality imagery.
At least in the pre-COVID days, if you had a viewing party (e.g., sporting event) with a large number of guests (like 10-12), having a screen with a wide viewing angle would be very important.
Today, if you're social distancing at home with a couple of family members at most, maybe the viewing angle feature is less important.