Yeah, mini albums are really just a way to release music in a more profitable way by cutting time and costs, and then selling it for just about the same as a full-length album.
In general though it helps a lot with the music cause instead of releasing a few good songs and a few so-so filler songs, you pick the best 5 or so songs that fit well together. That's different from singles as you get the "good" a-side, and then the "not as good" b-side(s).
That general assumption doesn't seem to work here though. It sounds like to me they put the song they want to promote and then add fillers, with Genie having the not as good fillers. Which is why these mini albums just sound like longer singles.
If you put the two mini albums together, I'd say it's just as good as their debut full length. Which isn't really a good thing imo since it should have been better cause they had to have a number of decent producers wanting to cash in on them now.