Are there any pistol accessories that are genuinely useful?

So two of my handguns have rails and mounting spaces for any number of goofy tacticool stuff. But none of it has appealed to me at all. I shoot just fine without an optic. Lasers seem like a gimmick that don't work either because the dot isn't visible enough or because the dot never stays zeroed. And a flashlight doesn't seem necessary when I can just also hold a flashlight. Is there anything I'm not considering that might be more useful?

An underbarrel shotgun would be awesome but I doubt they're made small enough for a pistol lol

If it helps at all answer, my guns are largely for shooting at ranges, and also for the hopefully never self-defense situation.