Does the absence of احتلام (wet dreams), despite religious commitment and adherence to the etiquette of sleeping, indicate a result of this commitment, or is it a disease or weakness in the reproductive system?

Lack of nocturnal emission might be due to commitment, as nocturnal emission often comes from Satan. Thank Allah for your well-being and do not succumb to whispers (waswas), for the presence or absence of nocturnal emission has no bearing on the ability to marry. Occupy yourself with what benefits you and supplicate to Allah to grant you a righteous wife and goodly offspring.