If only the container was an issue, you would have a direct stream which doesn’t impact quality, it just repacks it in a container that is compatible with the client.
You can see the transcode reason on the dashboard by clicking on the i symbol. Start playback on android TV, open jellyfin on your phone and you should see the transcode reason.
It’s just incredibly funny that the site that tried to fight spam and ad bots because it harms user experience is now implementing spam and ad bots to harm user experience.
Obviously that’s okay because it’s their spam and ad bots!