• No dedicated equipment necessary. I could use whatever hardware I want in whichever TV I want. Apple TV, Roku, Chromecast, Xbox, Amazon Fire TV, iPhone/iPad, computer browser.. it didn't matter. If I wanted to watch TV on it, I probably could. This made it really nice to have every service I use all in the same place (ie Netflix, Plex, Amazon Prime, Hulu, Disney+, etc.). This also means no equipment fees at all. No $15 for the first TV and $5 for every other TV I want it on.
• There are no contracts. I can sign-up or cancel at will (and I do for at least two months every year). Saves a decent chunk of change when our usage would otherwise be minimal, and it's a completely no-hassle experience. Never have to negotiate prices, never have to work through multiple layers of customer service. Just log on, cancel, call it a day.
• The mobile aspect is understated. The viewing experience and user interface is just as good on my phone when I'm a passenger in the car, or out at the grocery store, or at a family reunion, as it is on my TV at home (aside from the screen size difference). I watch live TV on my phone almost every single day.
• Unlimited DVR. I record everything. Every sporting event from 10 different leagues. Every show I'm mildly interested in on every channel. It's always there if I want it and I never have to worry about running out of space or deleting anything. This also means that if some random game is airing and I want to drop in on it, I already have the full game recorded and can go back to something crazy that happened that I heard about online.
• Multiple simultaneous streams included with the base cost. For many people, this means that their kid away at school can still enjoy live TV from the home service, or some people even choose to split the plan to reduce their costs.
• Fewer points of failure. I never need a tech to come out and adjust my satellite that has become misaligned in a storm, damaged cables from a neighbor digging in their yard, or any equipment acting wonky. Sure, none of these issues are that common, but they have all happened to me while I was subscribed to Xfinity or Dish and I had to pay $50 minimum to have someone come out and fix it each time. Additionally, I didn't have to pay anything for installation or wait around to get access to the service.

I get all of these great features, and I still pay less than I would be if I were using a traditional cable/satellite service. Sure there are some downsides to it, there are a few channels currently unavailable to me. There have been some big price hikes in the last 18 months. Streaming is generally ~15 seconds or so behind satellite feeds. But the positives have far outweighed the negatives to me.