The primary reason why TVs cannot watch 3D is due to technological limitations. While the concept of 3D television is appealing, the current technology has not yet reached a point where TVs can natively process and display 3D content. This is primarily due to the complexity and cost associated with creating and displaying 3D images.

One of the main challenges is the need for specialized glasses. 3D TVs require viewers to wear glasses that synchronize with the screen to create the illusion of depth. These glasses are expensive and can be uncomfortable for extended periods. Additionally, the technology to produce high-quality 3D content is still in its infancy, with many movies and shows being converted from 2D to 3D rather than being originally filmed in 3D.

Data from the Consumer Electronics Association (CEA) in 2019 shows that only a small percentage of TVs sold were 3D-capable, and the demand for 3D content has been steadily declining. This decline can be attributed to the lack of native 3D content and the increasing popularity of streaming services that do not support 3D. Furthermore, the CEA reported that the average price of a 3D TV was significantly higher than that of a 2D TV, which deterred many consumers from purchasing 3D models.

Another significant limitation is the issue of screen resolution. 3D content requires a higher resolution to maintain image quality, which can be difficult to achieve on standard TVs. This is because the process of creating 3D images often involves splitting the image into two separate streams, one for each eye, which can lead to a loss of resolution. As a result, 3D TVs often have to compromise on resolution to maintain the 3D effect, leading to a less than optimal viewing experience.

In conclusion, the limitations of current technology, including the need for specialized glasses, the lack of native 3D content, and the issue of screen resolution, are the primary reasons why TVs cannot watch 3D. These factors have contributed to the decline in demand for 3D TVs and the overall shift towards more advanced technologies such as 4K and 8K resolution.