If you are having issues with local TV channels on the Spectrum TV app for Roku, you can still get your area's local stations on YouTube TV or Hulu with Live TV. I have both, and use one or the other on those rare occasions when my cable service (Spectrum Choice with Roku) goes out.
These streaming video services are not, however, available in every part of the United States, although they do cover a large part of this country and service is coming to new areas all the time. I would suggest you check to see if either service is available in your area before subscribing, although you may well be advised during the signup procedure if either is not available at your location.
Service outages, whether caused by equipment failures, weather, or both, are unavoidable; they do occur every once in a while, and are beyond the control of the cable operator. I am sure Spectrum is not deliberately cutting your service just to force you to watch other channels or to use alternative services.