How does ego, pride, hinder spiritual growth?

There is no spiritual growth. “Spiritual” is really a vague, undefined concept.
Ego and pride are virtues. It’s good to believe in yourself. It’s only when you take them to extremes and think of little else besides yourself that they become harmful to your personal growth.
(I know that “personal growth” doesn’t sound as mystical and exciting as “spiritual growth”, but it’s a more accurate term.)

By disallowing the fact that there is room to grow. If I accept all my beliefs as patently true, then I stop searching for the answers.

Material desires are the product of ego and material desires aren’t compatible with spirituality. You can be spiritual or you can be materialistic but not both.

because when you can only see YOU … you cant see further than that

ego and pride without understanding distorts your perception and your intentions. humility is the path to understanding.
understanding can cultivate pride and egotism, but also places checks on them.

Your heart is closed off to that which is of God. The original sin is pride

If one is egotistical and proud, they won’t allow anyone to teach them new things. They are pretty much turned into “Know It All’s”.
Prov. 16:18 says that “pride is before a crash”.
Prov. 22:4 says “the result of humility is riches and glory”.
So one would have to humble oneself in order to grow in more spirituality and become ‘spiritually’ rich.