The way I see the relationship between combat sports and Pure Krav Maga is that the human body was designed to use its brains to develop armed and unarmed combat - Using a weapon, using impact blows and kicks and using push and pull and gravity blows combined with leverages for breaks and tears in a logical manner from a whole combat perspective that drives the tactics.
For Martial art and combat sports that decided to concentrate on only one or few type of moves like boxing, jujitsu or muay thai or weapons systems, these restriction might have developed compensated abilities with the quest to resolve hand to hand combat scenarios with limited set of options.
If you are looking for hand-to-hand combat and self defense you need to be exposed to enough methods of attacks and counters so you get a set of principles that can help you cover what you were not exposed to.
Surely if you become a combat sports athlete you will be in good shape, less likely to worry and fear of a physical confrontation but you also might get a false perception of reality as your school does not expose you to realistic options.
Many sports simplify the complex tactics of hand-to-hand combat and turn one training drill or another into a quest of getting an advantage by succeeding in taking someone out of balance, or restricting his movement and tiring him out, or inflicting enough pain so he will give up, or simply knocking him out - having him under the control of the spell of a blow.
While it demonstrates great skills of athleticism, yet it only deals with few agreed upon aspect of reaching pressure points. It is not that one way of fighting is preferred over the other.
Use the Opportunity to View the Complete Israel Defence Forces Krav Maga Curriculum Training Sessions
Get the Training Manual: