I think it would be worth making the finals, even if there were no hope of beating the warriors.
Making the finals once gets you experience that will be valuable in getting there again. Two to three years from now the warriors won't be unstoppable. Maybe even next year they won't be unstoppable.
But, the way the season has gone so far, the warriors are irrelevant because the Celts will have a really hard time just getting past the sixers, bucks, pacers, and raps.