They’re probably talking about Samsung TVs, not their android phones/tablets. Installing jellyfin on those things can be a chore. My experience with LG was similar. The official build was out of date and riddled with issues that didn’t exist on other versions. It refused to play videos that worked well enough on other devices, transcode or no.
That small inert lump of metal can have jagged edges that can cause injury later on. It also definitely is loaded with dirty crap that will cause infections. Overall it’s rarely “fine” to leave random, unsterilized foreign objects inside the body.