That's pretty much it, you can jailbreak the Firestick and utilize a bunch of those "illegal" streaming services, thus not paying for any of them, Kodi for example.
From what I recall it's a bit of a pain in the ass to setup, and you're chasing new steams/services on a semi-regular basis as their taken down.
https://www.firesticktricks.com/jail...ire-stick.html