A non-intelligent television is any television that basically only contains a screen and connections but does not have an internet connection or an operating system on which applications can be installed.
It can be said that the old televisions were not smart televisions or dumb screens even when they fulfilled their mission, that is to say to show the signal received by the antenna cable, satellite or cable, the signals that can be entered by HDMI, VGA, Scart and in the event that they have a USB connector, play content from a USB hard drive.
The main advantage of a non-intelligent TV is that it is a little more difficult for it to become obsolete due to neglect or lack of maintenance of the software by the manufacturer.
There are cases of large manufacturers that have launched televisions with operating systems such as Opera TV or NetCast and that have been discontinued or replaced, leaving users without the possibility of updating or downloading applications.
On a non-smart TV you can connect an HDMI Stick or media player such as Chromecast, Xiaomi Mi TV stick, Amazon Fire TV or Apple TV to be able to play content from the internet. These HDMI players have built-in operating systems such as Android TV, FireOS or tvOS that are widely used and have less risk of being abandoned or not having the video on demand application of the service you need.
Another advantage is privacy, smart TVs force us to accept their terms and conditions, among which are the sale of our usage data and content consumption. This is a very lucrative form of income for manufacturers, which can even be higher than the income from the sale of devices themselves.
Using an HDMI player we can choose to disconnect it at any time so that it stops collecting information, in addition to the fact that they cannot access data from the television itself, such as the number of hours it is on or what antenna or satellite television channels we are watching at any given time.
Obviously these HDMI sticks have their own privacy and data collection terms but they are limited to the use of the device itself.