Marriage is a great Sunnah of Islam. It is not befitting for a Muslim to not marry (without a valid reason).
There is a hadith in which Nabi sallallahu alaihi wasalam) said to that sahabah that wouldn't get married without a valid reason.
Nabi saw said to him,
النكاح من سنتي من رغب عن سنتي فليس مني
"Nikah is one of my sunnahs whosoever turns away from my sunnah is not from me."
The importance of nikah can be realised from the above hadith.
However in the hanafi madhab it only becomes wajib (necessary) if a person is unable to control their desires and fears committing zina.