1. There's nothing good on, anyway. With hundreds of channels available, viewers can spend hours just flipping channels trying to find something worthwhile.

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This is one of the disadvantages of Watching TV. Are there any errors? Don't we have to put 'TV' after 'on'?

You can put "TV" right after "on" or not in that sentence. It'll make sense either way. It's a kind of slang, I guess, but people understand it!!

I think you should put the word TV anyway, but when you say channels in the sentence after, people already know what you are talking about. You can put it just incase but you do not have to.

Yes, you are correct. It would be more grammatically correct to say "There's nothing good on TV, anyway." The word "TV" should come after the preposition "on" to specify that you are referring to the television as the source of content.