Got the game early, went inactive for two years or so, came back to arena packed with R7 squads

I wouldnt say you cant be ever competitive in arena again.
Status quo is: You need a GL but its not that important what GL exactly. And I dont think this will change drasticly in the near future.

So with focus and a determed farm it is possible to get to the high spots. But it wont be easy nor fast