Mark 4:11-12, Luke 8:10 & Matt. 13:11-15 says that Christ spoke in parables so that the multitude in ‘seeing they would not see’ and ‘hearing they would not hear’, etc.

ESV (Mark 4:11-12) 11And he said to them, “To you has been given
the secret of the kingdom of God, but for those outside everything is
in parables, 12 so that “they may indeed see but not perceive, and may
indeed hear but not understand, lest they should turn and be
forgiven.”

(Luke 8:10) he said, “To you it has been given to know the secrets of
the kingdom of God, but for others they are in parables, so that
‘seeing they may not see, and hearing they may not understand.’

(Matt. 13:11-15) 11And he answered them, “To you it has been given
to know the secrets of the kingdom of heaven, but to them it has not
been given. 12 For to the one who has, more will be given, and he will
have an abundance, but from the one who has not, even what he has will
be taken away. 13This is why I speak to them in parables, because
seeing they do not see, and hearing they do not hear, nor do they
understand. 14Indeed, in their case the prophecy of Isaiah is
fulfilled that says: “‘“You will indeed hear but never understand, and
you will indeed see but never perceive.” 15For this people’s heart
has grown dull, and with their ears they can barely hear, and their
eyes they have closed, lest they should see with their eyes and hear
with their ears and understand with their heart and turn, and I would
heal them.’

What does this mean? Why do people say Christ used parables to help the people understand clearly, when these passages seem to say he did not want them to understand clearly? Are the parables meant to be concealing yet revealing the truth completely at the same time?