A few thoughts. I cannot understand why XFinity charges such a premium for TCM. You are not alone in your frustration. Yes, the Watch TCM app only lets you watch it if you already get TCM on cable or satellite. It primarily shows what is currently showing on TCM for that month. I still like it in case I lose the TCM picture due to thunderstorms (I have DirecTV) and it enables me to find it on the app which I stream with an Apple TV.
Since the Criterion streaming service plays a lot of classic films, some of the TCM fare shows up on that service. The HBO Max streaming app has a TCM "hub", but it is very limited and has way more modern films than TCM usually does.
There are ways to record from satellite and streaming boxes. I use a Hauppauge device which connects between my DirecTV box and my PC. The movies record in HD as they looked on TCM, and I can burn them to blank Blu-ray discs, AVCHD DVD discs or regular blank DVD discs.
Thanks for the comments and insights. We completely cut the CATV cord for cable tv. The Sling and Hulu Premium fees are outrageous. I killed Xfinity for the $100/month and don’t need a replacement streaming service for $70/month.
I still subscribe to Netflix DVD and get a lot of classics that way, but their library continues to shrink. I have a lot of films in my Queue, but every ti,e I look, another handful are moved to “Saved” which means they are probably gone for good.
I find I can get a lot of good DVDs and Blu-Rays at the public library. In the worst case, I buy a disk on eBay or Amazon. I just bought the Russian anti war film Blu-Ray “Come and See” because it wasn’t on any streaming service and the library DVD quality was so bad that it was unwatchable. Plus, the subtitles were mushy gray and unreadable.