I think even if you grind like hell also doesn't help much because of the caps. The most, you may be on par with the low spenders. But the gap is getting bigger and bigger. Sooner or later leaderboards will only be filled with spenders. Some have almost maxed out their char with rank 10 5/5 gems in all slots. Now in BG matchup, at least 1/2 the participants are equipped with wings in all sizes. Even if you hc grind as f2p, you are probably not even close to the 1st tier wings. 3rd tier wingers can easily 2-3 shot or 1v5 f2p, totally no fight. And now with China launch, not sure how it would affect SEA servers.
Having said that, the game was designed and intended to be that way.