This is an interesting concept and in theory not a difficult one to implement, but there's a good reason it hasn't been done. Commercial TV channels cost money to run and very few people are willing to subscribe to them apart from paying a provider for a TV package. Only state funded public service broadcasters are obligated to let people watch them for free and only the biggest ones, such as the BBC are ad free. If you want to watch commercial channels without having to pay to do so then you must endure the ads, that's the deal. If the advertisers stop making money, they'll stop advertising and the channel will cease to exist.
I never block ads on websites I support and in a few cases I pay a subscription fee instead of having to see ads. I don't have any ethical issue with blocking ads on the internet when they are unfairly obtrusive or clearly disreputable, but the ads on commercial television generally aren't as bad as you describe and they don't hamper the viewing of programmes.