Ranked Isnt based on Win Loss

Friend of mine just started playing has same win loss in ranked however is ranked much higher then me. I go up one at a time he skips up 3-4ranks. If competitive is based upon win loss then we should be same rank. Also haven’t played overwatch in a long time so I have no idea what my ssr or mmr is. I haven’t played in so long I should have been reset like a fresh account. I just want someone to explain to me why someone who has never played before is completely outplacing someone who has played though not in a long time. When they have the same win percentage. Why am i being punished.