To me having mounted lights make all the sense in the world. Apart from that I also think having a small separate flashlight is a reasonable choice if you can operate and handle a firearm that way.
I have a light on my AR as well as another light on my Glock.
However, lights can interfere with pocket carry and / or holsters.
Therefore, some of my firearms do have lights and others do not.
In my case, I don't really expect a midnight home invasion, but I do realistically expect a midnight coyote at the edge of the woods perhaps going for my puppy. In that case the under-barrel illumination lights up the backyard.