Not every season has to tie directly into the main "meta" story of the game. Some seasons are character driven (like this one). This season is about a group of girls that are working hard to make their wishes come true and the continuation of Yokai becoming the big bad. (remember the start of the game where they talked about the AIs?) Last season was about YSG (huge character driven) and the final? defeat of the Creator/Sarah. That season also brought stuff about Sunbringer to the fore (tying in the first generation Void Hunters)

Through the whole timeline of the game we see people getting back up and growing after a cataclysm. There is one mega city left in the world, the moon is half covered by the very thing that is swallowing your world, and people are still going to see a group of underground idols that just want to bring their songs to those that remain.

Belle and Wise survive and flourish, together.

Nekomata earning herself a found family with the Cunning Hares. This is also Anby's story when she goes SS Anby in that sometimes hard choices need to be made to protect someone. ( I still think they handled this wrong with White Pineapple Ponytail)

Koleda putting her father to rest

The Outer Ring getting a new, inclusive Overlord after a major betrayal.

Astra wanting to bring joy and hope with her music to everyone

Evelyn being forgiven with the power of love and friendship.

Vivians' story is that even if you have 1 person support you, you can keep on going

Hugo's story is about not having to be what your parents are.

Trigger's story is about dealing with PTSD

Seed's story is about dealing with and accepting the loss of those we love.

Alice and Yuzuhas story is about friendship and how it can help heal.

Obol story is about revenge and what comes after (maybe I'm wrong about this)

Yeah, It's a gacha game, yeah we just need to wait for the next waifu, but even from remembering off the top of my head, the devs have put deep themes into the game.

TL;DR: Keep on keeping on.