What is the point to deap adventure mode?

i just got to that point. they stop giving you anything at that point . i can't buy the basic pack either 

Wow that is crazy!  Given how hard these levels get, throwing a few gems your way would only make sense.  Wouldn't have to be a lot.  

i not sure about gems with boss fights tho like i said it litterally just happened and i didn't get to a boss fight yet. my tablet is charging right now too 

It is because some of them are challenging, but have fun gimmicks and challenges sometimes. Like the one where the plant or zombie with the highest strength does a bonus attack at the end of its turn.

In its current state, the AI missions work for a few reasons:

1. To help new players gain hero cards, 
2. To help players beat certain quests that are more difficult in multiplayer (or without fear of losing rank and without having to wait to be matched in unranked)
3. To give a fun challenge.

Now, given that this game is in constant iteration, I wouldn't be surprised if in the future they do add some more substantial rewards to the adventure mode, which is why I'm only playing it if I need to beat a quest that is otherwise to hard in multiplayer.

I'm hoping they add more single player content in the future including a random battle (location & enemy) generator.

Then we can play as much as we want without worrying about running out of content.

Well, it doesn't take long at all for a FTP to get to the point where there is zero reward from deep adventure mode - just got there myself, after what, less than two weeks of very casual play.  Major bummer that they don't at least throw a few gems your way.