These channels generally require a TV provider to have access to them. That is their business model.
CBS is a bit special case for this, as you might get access to a local CBS station through (Premium plan) Paramount+.
You can get access to live/linear TV channels through internet streaming TV providers, which might be a good alternative to cable plans. For similarity, they also have packages of channels, so you get much more than you’ll select or want; that part hasn’t changed. you can choose from internet streaming TV providers like Hulu Live, YouTube TV, Sling TV, DirecTV Stream, Philo TV, FuboTV.