there is no need to; it is fine if you don't; unnecessary
Follows a verb (dictionary form or 〜する必要) to say that an action is not required. Often used to politely decline an offer or to reassure someone.
わざわざ来るには及ばないよ。
There's no need for you to come all the way.
心配するには及びません。
You don't need to worry.
does not match; out of reach of
Follows a noun to indicate that something is not comparable or cannot reach the level of that noun. Often used in the pattern 〜には及ばない to mean 'cannot compare to' or 'is no match for'.
彼の実力はプロには及ばない。
His ability is no match for a professional's.
この映画
This movie doesn't match the fun of the original work.
The verb 及ぶ means 'to reach' or 'to extend to'. には及ばない is its negative potential form used as a fixed expression.
必要はない also means 'there is no need', but is more direct and less polite than には及ばない, which often carries a softer, more considerate tone.
Formed from the particle に, the topic marker は, and the negative form of the verb 及ぶ (to reach). Literally 'does not reach to', it developed into a set phrase meaning 'there is no need' or 'cannot compare to'.