This is more of a tangent to what you’re saying but you inadvertently touched on another issue.
Firstly, in terms of what you’re saying. A GL shouldn’t be a sure thing. Ideally they should be used offensively for maximum utility out of the characters since they can be used to solo many teams out there. Defensively I don’t think it should be impossible but at least challenging to take out a GL with a non GL team.
Now the issue I want to highlight that you mentioned is the cost to leading to the GL.
Characters and such are fine. My issue, and purely my opinion, is that the light and dark currency grind is a dated and an unnecessary additional grind on top of an overly extensive grind. I would almost recommend to do away with that system completely as I don’t see any benefit whatsoever to anyone at all to have it in place.
What I do think that CG have in their mind is that the additional grind will make people spend money on crystals to then refresh energy for the currency farm. But considering how far you need to get just for this grind to even start, they really need to give the players a break on the money they can squeeze out. First and foremost, this is a game. Sometimes they need to be reminded of that and hopefully listen.