Looking back on your game history, OP, you would definitely benefit from limiting your opponents to "My level only" (use the cog), although as lots of people have already pointed out this is based on Arena Level not Elo.
However at this point in the season, it's a pretty good chance that anyone with a very high Elo will be in Elites by now.
As someone who plays a lot of games in Arena, I honestly don't think it's
that bad as long as you use the level filters when you're new. Yes, it's prone to manipulation but if you measure progress by Elo, so is that.
Personally, I would leave people in the league they finish the season in (maybe relegate the bottom 25%), so you'd keep the really high level regular players in Elite to scrap it out right from the beginning but that's just faffing about at the edges.
It's got the highest level of competition on BGA, so that's what you should expect. I know that if I think I'm good at a game before I go into Arena, I will rapidly discover that I'm not