The levels are there to make you pay. From a business standpoint, it would be suicidal to make them meaningless.
With that said, they could rework how system treats levels. If you don’t go down in leagues after every month, you wouldn’t be facing level 11 units in Diamond League by people who lose on purpose to kick around other players. The first couple of months when this game came out, things were where they were supposed to be. You didn’t see level 10 units until you hit Masters. Level 11 units were at High Masters and Tiberium only.
But because you keep getting pushed down a league every month, people abuse the system and purposely don’t advance to the next league so that they can use advancing players as whipping boys for their own amusement.
If every month nothing changed, as you move up, you would only encounter people with units the same level as you or maybe one higher. The way it is now, you are facing units that are sometimes 4 levels above yours.
EA can also fix this by lowering the level caps when you go down a season but they won’t do it to force you to pay.