@tuatara1 welcome to the world of manga, lol. SFX are used to help set the tone for the reader, so whether the SFX says something like "sulk" or "silence" or anything else that really doesn't make a noise, it's always meant to be helped to flesh out what's going on. If you only had SFX that made noise then you'd lose out on a lot of detail. That or you'd need a large amount of "aside" text to make up for it, and those can be even messier than SFX are...
But that's my interpretation of it. I've read manga for decades, and I even work on some for my irl job. I've never been annoyed or hateful of SFX, except for ones that don't really get translated and are left up to our imagination for what they mean (I really should learn to read Japanese sometime...that would fix that problem!)