When I first got serious about TVs, I did get a pro calibrator. But I honestly did not like the results. I found that its a very personal thing (especially contrast and saturation). I also found that pro calibrators mostly only calibrate to the standard which is geared for a "near black-out" room and it will not look good as soon as you have even a moderate amount of ambient light.
So, after that, I decided to learn how to calibrate myself. I did pretty good and even posted my results here (many years ago). It only cost a few hundred to get a cheap color meter but it took many, many hours to learn how to do this correctly and to learn the low level calibration menu settings for the TV. Getting to the grey scale number is much easier today (no long need special service menu for many TVs) but its still fairly complex. But, for me, that is the only correction (i.e. color) that really needs correcting.
Anyway, with my most recent TV, I have not done any "pro" type of calibration. I did try to do a bit of grey scale changes but I found I had a hard time correcting yellow (still looks too red) without messing up other colors etc. In the end, I gave up and just focused on color/saturation/contrast/gamma etc. Those I feel I have a pretty good setup for my taste.
I would like a pro calibration to see if the colors could be a bit more accurate but I hate the idea of spending a few hundred bucks on a decent calibrator. I think this is the main reason most people don't bother. They either don't know what it is, or that they may need it or they know but don't want to spend up to 30% of the cost of the TV to "calibrate it". It is very expensive relative to how cheap TVs are today. But if you have money to spend and an expensive TV, it may be worth it but don't expect anything great if you already adjust/tweak the settings and like what you see. For some, it will be a much valued improvement, for many, I suspect, its not really worth it. I see TVs at other peoples places and I can't believe the contrast brightness and color saturation they "prefer". I think those people really don't want a pro calibration and would just mess it up anyway