There is something to be said for bringing your phone to protests so you can livestream them to the world when the authorities use heavy-handed, violent tactics to stop them.
In all honesty, it would probably be best to have a dedicated device for that situation as well so that if they choose to search it then all they will get is the footage from the event.
While I agree that filming is important, it’s also important to remember that between the J6ers being dumb fucksticks and their social media site being absolute dogshit, a lot of them were caught because EXIF data wasn’t scrubbed. Having one’s phone with you could end up being the thing that gets you prosecuted.