With Charter Spectrum you can subscribe to the App-Only version of their Cable TV service (and I think this is true for other major cable providers?). I use this in my personal home and my STR property. It adds around $40/month to the cost of your internet service.
Guest simply needs to turn on the TV and go to the Spectrum app on the Roku (or any similar device), which I tell them on my "house rules/faq" sign right at the front door. Once in the app it looks just like any other Cable TV interface. Never had anyone call to ask how to use it, although to be fair, I'm not sure how many people watch TV. Either way- I prefer this for several reasons:
-Cable boxes are an absolute scam. The cable companies require you to pay extra for something that you probably don't even want, given that they provide no value and are also another clunky device requiring wiring, space etc. Cable companies have even lobbied congress to allow them to force them on consumers for each TV.
-No clunky remote with 50+ buttons that hasn't been redesigned since 2003 that guests need in addition to 1-2 other remotes to perform basic functions. Even if it can be programmed to be a one-stop remote they are still confusing and unintuitive.
-Quick access to other streaming apps and the guests can use their own log in. I don't subscribe to any, but if they want to use them bad enough, they will dig up their password and make it work.