A few decades ago, leaving the TV on for long periods of time was a big mistake. At that time, most models had LCD screens that could burn out from transmitting an image for too long. The first plasma screen televisions were even more susceptible. So, if you still have an LCD TV without LED backlighting or a plasma TV, leaving it on all the time will probably damage your screen over time. But current televisions also have their problems, especially the cheaper ones.
Be very careful with very cheap televisions! It's expensive!
Nowadays, most televisions have LED-backlit screens, which do not burn out as easily due to prolonged use. So, chances are you can leave your LED TV on the Netflix menu for several hours without worrying about the big red N burning in the middle of your screen. However, there is something much worse that is usually present in very cheap televisions. For this reason, they tend to break down much faster.
Smart TVs are more affordable than ever, but manufacturers sometimes cut corners to keep prices low. The most common ailment of today's smart TVs is poor heat dispersion. Because they have processors and other heat-generating hardware, smart LED TVs can become hot when left on for a long time. This can damage its internal components and significantly reduce its useful life. In fact, many experts recommend turning off the TV every few hours to let it cool down. However, this is not the case with more expensive televisions where everything is thought out in detail.
This is why you need to be careful about what you buy. A television from a little-known brand, which is also cheap, without even being on sale, could be a big mistake. That being said, cheap can be very expensive.