Worth noting the maintenance and cleaning also feeds significantly into cost and function. Reducing the wear on the actual used rifles and barrels and functional parts over the course of 10s of thousands of cycles per weapon comes with notable cost savings.

There can also be notable advantages in some countries where for example guns are more restricted and they have to be very very specific about brass collection. You'll see in places like Japan and Korea they often have a gun running next to someone doing drills with a net to catch brass because they can't allow even a single casing to be missing as they don't want them to be stolen and potentially reloaded or sold to the public etc.

The version in OP probably doesn't fire any projectiles but either using ones like these which shoot lasers like MILES gear or ones that actually shoot a bb projectile are also good for force on force at close range; cheaper and more reliable than simunitions.

Basically any time you're not actually really specifically doing something where the training of marksmanship at notable range is the primary concern, a training aid like this can be useful and significantly cheaper long term.