Raiden lack some stuff to be competitive, but certainly is not lack of combos.
He is a far / mid range character....but in this version of the game it is not that difficult to get near the opponent....and once they-re in....Raiden is fucked.
His strings are so negative....you can't hit confirm like scorpion for example, who tries to guess with safe options and still has a chance to get out or continue the pressure on block because his buttons are decent.
Storm cell is not safe on block....and when he is safe (like b1 2 / b3 1), even with push back, he is in trouble.
It seems like he was projectes to be good when dashes and high pressure weren't a thing....but the game changed and there is no way to use him competitively right now.