Well it's just..
2. Everyone was much weaker then... so being a "ninja" was something the main cast followed more..
3. When older their op... and powerful so things are much more over the top.. (may just be me but I like it, really makes you look back and see how far naruto has grown..power wise, maturity and his mind set)
I don't know... I say you can't look at naruto as bits and pieces... you have to look at the entire picture...
It ain't like dbz or one peice... It has one clear objective and it progressed over each ep.....
So it's all one big plot driven show..
when you say gaiden... I assume you mean just them older... which includes naruto the last (don't think that's cannon thou) and boruto the movie +which is cannon)
Kishi still has that skill where he plays with your nostalgia throughout that