The only freerolls worth playing are those with 1st place finish being 500$+ (preferably more). If you DO happen to win it, you want to win 'big'.
For example, idk if they're still going on but party poker had daily 5k freerolls, with first place finish at $1.2k iirc. Played a few of them, got to final table in one, first or second hand I shove AI preflop with AK against JJ and lose. Still made 64$ or something.
Also some satellites are worth playing while playing cash games if the player field is small. Got into a $200k+ tourney through 50 seat frenzy once in party (ticket alone worth 220€ or something), lost to a runner-runner straight with aces before ITM though.