Why were there so few historical records from Jesus life?

If the world doesn't recognize or acknowledge what is written about Him as it is, more wouldn't make any difference. God's inspired, Divinely-revealed Word is for those few Faithful whom He is "calling out of the world, now, for His Holy purpose" [sanctifying]; who "Believe" and "Love" and "Cherish" the few Words that are recorded. They're not for the whole world to grasp for the time being. The world is unable to "hear" God's Word:

"Justice - do you rulers know the meaning of the Word? No, all your dealings are crooked; you hand out violence instead of justice. These wicked people are born sinners; even from birth they have lied and gone their own way." (Ps.58:1-3 NLT New Living Translation)

What God has caused to be recorded is sufficient for His Faithful servants.

"'...I told you that everything written ABOUT ME by Moses and the prophets and in the Psalms must all come True.' Then He opened their minds to Understand these many Scriptures." (Luke 24:44-45 NLT)

"For the Word of the LORD holds True, and everything He does is worthy of our Trust." (Ps.33:4 NLT)

"O God, I praise your Word. Yes, LORD, I praise your Word." (Ps.56:10 NLT)

The time is coming when the Word of God will see fulfillment, and all the world will Understand it. But for now, God's Word is the source of His Wisdom, Knowledge and Understanding for the character-development of His Faithful servants; so that one day in the future, they may teach the nations God's ways:

"...Joseph was sold as a slave... until the time came to fulfill His Word, the LORD tested Joseph's character. Then Pharaoh sent for him and set him free; the ruler of the nation opened his prison door. Joseph was put in charge of all the king's household; he became ruler over all the king's possessions. He could instruct the king's aides as he pleased and teach the king's advisers." (Ps.105:17-22 NLT)

"We can rejoice, too, when we run into problems and trials, for we know that they are good for us - they help us learn to endure. And endurance develops strength of character in us, and character strengthens our confident expectation of Salvation. And this expectation will not disappoint us. For we know how dearly God Loves us, because He has given us the Holy Spirit to fill our hearts with His Love." (Rom.5:3-5 NLT)

God's Word is about "quality"... not "quantity." He has revealed and recorded the exact amount of Knowledge about Himself sufficient for His Faithful servants' development and growth. Otherwise:

"...I suppose that if all the other things Jesus did were written down, the whole world could not contain the books." (John 21:25 NLT)