Board Thread:Theories and Speculation/@comment-36649908-20180820043658/@comment-31099706-20180820110508

It can also be loads of training and special chakra/bloodline and talent. Guy was able to get as strong as Ten Tails Madara(even it was over a price) and Minato and Sarutobi were stronger than usually trained/kekkei Genkei Shinobi.

So, from what I can say, even without a special gift like the one Naruto and Sasuke got, one can train themselves with the benefit of their own special bloodline to get stronger. Though this may not be the case.