I actually thought all the leagues benefit in different areas. You get more chests in the lower leagues and better chests in the higher leagues.

I haven't played in the Gold League this season, but that could potentially be the sandwiched league whereby the chests you get aren't that much while the rewards don't fully compensate for the decrease in chests. Also Gold League in my previous experience is one of the most competitive as you have heaps of maxxed players trying to push into Diamond.