...but why tho.

Why would I want to spend Trophy Crysals to advance a series faster to get more Trophy Crystals and eventually the unique stuff?

You get like a level in 2-3 matches early on, a bit more later down the line. You have four months to do it.

The idea of it is to promote playing current Series, so mechanics allowing to reduce or skip this sound... counter-intuitive from a design standpoint.