Commercials on cable are fully skippable, since the first DVR in 1999. It's streaming that takes that freedom away.
Whenever I'm in the US and turn on a TV I'm always amazed at the amount of advertising and the effect it has on the media itself. One of the effects of streaming services was that it allowed script writers and producers total freedom from having to structure a story around the ad breaks.
Whenever I try to watch syndicated US tv here in the UK — e.g. The Simpsons — it's incredibly painful because the ad breaks don't line up, so you often get a 'false positive' and/or a 'false negative' that really affects the experience.
The comment I responded to suggested that it's impossible to record video delivered over the internet, which is obviously insane. Were you thinking of something different?
The comment you replied to was pointing out that it was possible to record from cable TV with DVRs and that they had a feature to detect commercials and either skip recording them or allow you skip them en masse during playback.
It is quite difficult to record video from many services. Harder still to do it in an automated way like a DVR.
Cable DVRs have to actually capture and record the signal into a ring buffer, and if it isn't integrated into a cable box[0], it has to come out of one, with a complicated setup of IR blasters to have your DVR tune the cable box to a specific channel. And of course you have to actually pause the video or record it in advance in order to get commercial-skipping capability.
Cable ad skipping is entirely a technical problem, streaming ad skipping is entirely a legal one.
[0] You were supposed to be able to just get a CableCARD, but the cable companies fought tooth and nail to force you to