I mean, you are on a privacy subreddit, e don't mention how much exposure you're willing to tolerate, and exposure to who.

With a Chromecast your streaming provider knows what you're watching, and Google know what you're watching.

Using a degoogled android means giving up on high end widevine support, which means that even if Netflix (or everything else) works, you'll be stuck at 720p low quality.

By pirating, putting everything on a Jellyfin server, then streaming via upnp no one is watching (maybe your TV manufacturer, depends) and maybe you don't even need a streaming box, but of course a used Nvidia shield with lineageos will make for a better experience.