Plus, a lot of people may get quite skittish when there’s a red dot pointed at or near them.
Don’t ask how I know, but a gunsight laser (like you’re thinking of) works like crap in daylight. That’s all Hollywood drama anyway, they’re only good for a few yards before they either fade out too much or shake like crazy from your slightest movement.
A cheap little sight and a hotshoe adapter is all it takes. Align the dot in the sight with the center of your viewfinder at maximum zoom, and you’re all set.