The parables make information, truth as it were available to those who have an appetite for it.
The purpose is not to make the truth clear and easy to understand.
Only certain people, those who do have ears to hear, will hear, and understand and bear fruit. The dumb masses will simply keep plodding on into the judgement.
10. And the disciples came and said to Him, “Why do You speak to them in parables?”11. He answered and said to them, “Because it has been given to you to know the mysteries of the kingdom of heaven, but to them it has not been given.12. “For whoever has, to him more will be given, and he will have abundance; but whoever does not have, even what he has will be taken away from him.13. “Therefore I speak to them in parables, because seeing they do not see, and hearing they do not hear, nor do they understand.14. “And in them the prophecy of Isaiah is fulfilled, which says:
‘Hearing you will hear and shall not understand,
And seeing you will see and not perceive;
15. For the hearts of this people have grown dull.
Their ears are hard of hearing,
And their eyes they have closed,
Lest they should see with their eyes and hear with their ears,
Lest they should understand with their hearts and turn,
So that I should heal them.’
16. “But blessed are your eyes for they see, and your ears for they hear;17. “for assuredly, I say to you that many prophets and righteous men desired to see what you see, and did not see it, and to hear what you hear, and did not hear it.
PS: The parables are actually quite scary because it is extremely obvious that the Father expects high performance and growth. The mantras of supposed "love and grace" of the average fearful and fruitless Christians are just part of the disobedience of this "human rights" age. The parable show God expects success. This success is not accomplished by human effort but by God Himself, though Christ, in us. Amen!!