https://www.youtube.com/watch?v=lSWyAQe5K7k

https://www.youtube.com/shorts/EqAYUb0uYn0

What's most misleading about Hollywood silencers isn't the sound of the gun firing, but the sound of the round striking. In suppressed weapons, the bullet impact is often significantly louder than the weapon firing and should be clearly audible if it's hitting a solid surface.

So, it's a bit like complaining that tinted windows work better to reduce sunlight on TV than in real life. Or conversely that people whispering in the movies are way too loud, since you shouldn't be able to hear it all the way at the back of the crowded theater.

Also, sound effects are very stereotyped in the media. They are nearly a symbolic code, not realism. Hollywood shoes don't sound like shoes. Hollywood beverages don't sound like beverages. Hollywood clothes don't sound like clothes. Hollywood sex doesn't sound like sex.

Also, these conventions were being established for worse sound systems in old theaters, TV, etc. You cannot reproduce actual gunshot sound experiences in a movie. They are already "silenced" just to fit into the playback environment. So what else can you do to portray a suppressed weapon after that? Of course, you'll need to reduce it even further to make it unambiguously different.

Edit to add: I recall how Dirty Harry's magnum got what seemed like a new sound effect at the time. Not only is the sound smeared out in time, it has a ragged edge like a clipped signal. It is reminiscent of the recorded sounds of space launches that were culturally widespread by then from the Apollo program.