The main advantages of streaming are portability and the ability to pick your content and not pay for content you don't want. "most" shows - especially network ones, are simply re-broadcast, commercials and all. Heck network shows have commercial slots built in. You can binge watch some old shows commercial free, and as you found out, a 30 minute show is about 17 minutes long.
We have a lot of streaming networks, sling, Hulu, Netflix, HBO max, Apple plus, and all those together don't add up to what we were paying through Comcast. Like another poster said, I DVR shows and scan through the commercials when I watch them back. Some streaming services have caught on to this and disable fast forward controls during playback. Subscribers only pay a portion of a network's revenue. Most comes from advertisers. And if you want to get rid of commercials, you will pay through the nose to offset that revenue.