Dude I totally agree I'm a bit disappointed when all naruto can do is a 3punch 2kick 1rasenagn/rasenshuriken combo, its getting pretty shameful. But in away naruto is at the average level for number of techniques at his age just look at his pairs. everyone has basically one base jutsu that they use, except sasuke. Sasuke has unlocked both his elements on his own while naruto only has one that he wouldn't of been able to discover on his own. Compared to sasuke naruto is lacking techniques he only has rasengan and shadow clone, he needs another jutsu. U_U
but dude how often does sasuke even use his fire jutsu these days, he basically relies on ms and lightning.
Naruto for his age has more destructive jutsu than most in the series.
Its not usual for a ninja to have that many high class jutsu except for kages. If you look at that way Naruto is more dangerous than those who know a lot low classed jutsu.
shadow clones(his first jutsu) - A class
Rasnegan(second jutsu he learend) and those MASSIVE ones too - A class
Wind rasengan - Greater than S-class according to kahashi
Sage mode - Only jiraiya and him have used this jutsu among humans.
Fox mode- obviously something Naruto has only access too at the moment.
Now hes working on another rasnegan variation who knows what side affects that may have.
Naruto has more high class jutsu and RARE jutsus than most. That's why his techs work in most situations and doesn't need to use many jutsu.
Back to you OP,
Your right at the start of the start of part 2 elemental jutsu came in the picture a lot, but when the rinnegan came in the picture Yin and yang is focused on. Kishi has spend a lot of time on elemental elements now he must spend time on the last element he didn't explain very well at the start part 2, yin/yang.
Kishi in my opinion is covering all bases at the right time, that's all really.