Is it normal for cheap LED TVs to have poor uniformity?

My parents needed a new TV for their living room since their old one broke. My parents don’t care much about quality so they agreed on getting something cheap. So they got this 43” Westinghouse Roku TV at BJ’s.

https://www.bjs.com/product/westinghouse-40-fhd-roku-tv-with-3-year-coverage/3000000000005573777/

The picture quality was surprisingly good, but the first thing I personally noticed was the poor uniformity. Like when you open the YouTube app, you can really see these faded vertical lines/dirty screen effect on the gray background. And you can notice it when there's panning shots as well. I mean, the picture quality is pretty good for a cheap TV for that size, but the poor uniformity shocked me a bit, though of course, my parents didn’t notice it.

Is it normal for cheap LED TVs to have poor uniformity?