One of the reasons LEGOs will probably still be around in 100 years is because of how utterly dynamic they are. Given enough time and attention, a person can seemingly build anything; a car, a spaceship, and even a working LEGO Desert Eagle.
No. Really. A Youtuber that publishes videos under the name Snyzer_Tech just dropped a short clip in which he shows off a completely functional Desert Eagle that shoots plastic pellets (which, of course, he also made himself). The young LEGO weapons engineer achieved this by putting together a complicated system of rubber-bands and plastic bricks to create a handgun that can fire off rounds from reloadable magazines. According to Snyzer_Tech the gun even boasts a jam-proof mechanism and a slide lock for quick changing magazines. You know. For fast action when the squirrels in the back yard get particularly ferocious.