Jirachi has been inderectly buffed. With an air ballon and special defense investment it can handle banded kyurem black, tapu lele, tapu bulu and some magearna well. It walls melmetal for a single turn, but it doesnt do much in return. It dies to leles shadow ball, but since ive seen so much "never run shadow ball lele" posts, its safe to assume they dont run shadow ball.
The main reasons jirachi has fallen are genesect and heatran. It barely scratches tran and genesect does 70% with a u-turn. Other counters include lando-i and cinderace.