The pistol emoji originally looked like a real gun. I think only Windows had a fake looking gun (more of a ray gun than a water pistol) initially.

https://web.archive.org/web/20150625033351/https://unicode.o...

The change to a water pistol started with Apple in 2016, and then other companies followed:

https://blog.emojipedia.org/apple-and-the-gun-emoji/