I'm glad to be able to bring my bikes indoors at home. They're safer than if I had to lock them up outdoors, and they aren't out in the weather. Not everyone is as lucky, and for those who can't keep their bikes inside at home, good locks are a must. The way things are these days, your bike wouldn't be safe on your front porch if it weren't properly secured.
Naturally I lock my bike to a solid object when I've ridden in to work, or when I'm out running errands. In the latter case, I bring along a heavy cable that has a built-in lock when I'm going to any place for the first time, and don't know what might be available for hitching up my bike. A U-lock is useless when there's no object small enough in diameter to let the U fit around it. I can thread the cable through the rear wheel and around a thick pole, and fasten the lock.Then I use the U-lock to fasten the front wheel to the frame.
In the case of places where I go often, and a lot of people are around, I find the U-lock alone to be adequate, at least in the daytime. I seldom am out and about at night; I'm of the early to bed, early to rise school.
Are all those locks overkill? Maybe. But peace of mind is worth a lot.