I totally understand that.

I myself think of a mid core player who invests lots of time into the game but doesn't have in super difficult content, for example savages and ultimates. This person would be interested in something like Bozja and getting all the notes, or someone who wants to all cards for triple triad. Something that can be long form, fun and engaging.
That's why I think a battle pass system could flesh out some concerns about dawntrail not having any mid core content. The new field op tried but ultimately failed as its not fun or rewarding and the raid is too difficult. Bozja was the perfect mid core content.

Edit* I forgot about the cosmic exploration. That was a good attempt tbh.