I have a smart TV and wouldn't mind watching some videos on it like I would on my computer. I don't mind an ad here and there, especially since I'm used to commercials on TV. The problem is some of these people who upload videos and/or have websites sometimes make the videos unwatchable because they try to monetize so much that there's a constant 30 second commercial every 3 minutes or pop-ups. And that's assuming you can get past the bombardment of ads on the site itself to even watch the video.
I was on one site where you would watch a video, the video would go black to load up an ad, and the ad + the sound from the video you were watching would be going at the same time, so you would have to rewind the video once the ad finished to see the parts you missed. classified_fu
I'm honestly not sure if you can without some hackary on your TV.
However, if you are willing to give basic networking some research to assign a specific DNS server to either the TV or the router itself, then set up some filters on OpenDNS you could filter out most of what you don't want to see, but it might have negative effects on your browsing you'd have to troubleshoot on a case by case basis.