That's what I've found.

I have relatively poor vision at night. Corrected, so focus is pretty good, but like most people it suffers somewhat in the dark, even worse if misty, foggy, drizzling. But I've noticed I can visually pick up cyclists much more quickly if their lighting is more attention-getting. And that means flashing some sort of pattern, other than strictly steady.

As some have suggested, multiple lights where the light pattern differs (ie, one stead, one slowly/randomly flashing) can draw attention where a single light can get lost in the visual clutter.

Myself, I run two red taillights, each flashing a slightly different pattern. Crazy bright, separated enough to be clear, and flashing to grab attention as early as possible. I run a single headlight most of the time, and it's on steady during runs in the dark, but I do a crazy-bright flash during the daylight hours. Riding as frequently as I do on narrow two-lane streets (without shoulders, with ditches), it's important to gain attention as early as possible in such places. I notice drivers drive a bit more gingerly when I've got the "aggressive" flashing modes on, yielding a bit more space around me as they blow by.