I hate Xfinity I've been with them for 12 years

I would suggest just getting a Roku and using it for awhile before making any big decisions about leaving anything.

You need internet (from someone.) Since you say you are a long-time committed customer of Xfinity, I assume that means you have other choices for internet. That is to say, I assume committed doesn't mean compelled!

Many apps are independent of any cable system, but certain name-brand channels that you are used to on cable may only be available if you also have cable. This is why I suggest you just get a Roku and see what's what. You may care about losing those channels or you may not. I think a person could just get Netflix or Prime and have more TV than he could ever watch. But it might not be the exact TV that you wanted.

Of course, there are also "cable replacement" type packages like YouTube TV. Though I think YouTubeTV is priced relatively close to what Xfinity gets for cable TV. It's hard to compare since channels and features are never exactly the same. It really comes down to which channels and features you care about.

Of course, Over-The-Air hasn't gone away, and you can get TV from satellites, etc...

I switched to Xfinity for my Internet and home phone about 4 years ago, and have never regretted it. CenturyLink could only offer me 100 Mbps DSL, and their service level had been deteriorating for a number of years. After four separate outages within about a six month span, I was fed up. Without moving to satellite (and Starlink wasn't really an option then) Xfinity was my only other choice. I was hesitant after having their TV service years ago (under a different company that was bought out by Comcast), but I was pleasantly surprised with it all. I started with 600 MBps for less than I was paying for DSL, and it's since been bumped to 900 (but real world I get Gigabit speeds) for the same price. The only outages I've had were with a large area power failure after a storm, and I would have lost DSL under the same conditions. I had issues trying to control my modem settings (Comcast locks some of the settings) so I just put the modem in bridge mode and use my own router instead. 

Obviously, you need an Internet connection to stream. If you use a phone hotspot to connect to the Internet, then no there's no additional hardware necessary. But if you're looking for TV service without subscribing to something like Fubo, Sling, or YouTube TV, then you need an outside antenna and be within the reception area for your local stations. Of course, that still don't give you many of the offerings that cable TV has, although the companies I mentioned above can provide them. 

Streaming is good, but not without its cons too.  One thing you might find leaving a cable/TV provider is that the collection of streaming app/services needed may end up exceeding the cost you were paying, depending on your wants and needs, due to the scattered nature, right now, of streaming services.  If a number of those channels you depend on with Xfinity cable are important, then streaming the Xfinity app with a streaming device (such as Roku) and dumping their boxes might be a cheaper/better option, but again that depends on what you want/need for the channels.  Ad free usually means older shows or reruns frequently of the same episodes and, usually, some type of subscription is needed to watch newer stuff or recently released episodes/movies, etc and live services are a bit all over the place and hit and miss when it comes to certain channels in how well they are supported by the owners of the app/channels.

One of my biggest frustrations with streaming is the lack of cloud recording with a number of apps, which is why I stayed with cable service and use streaming combined with their cloud services, especially for live events, such as sports games.