I use my bike(s) for everything, but especially to replace car trips.

Since that means they need to be utilitarian, both have front and rear bike racks and a place to hang a basket, if needed. They also both have fenders.

My MTB does all the heavy-lifting, bad-weather, off-road capable riding, so I can attach a trailer to that one, use studded tires during the winter, etc.

It's also steel, so even though it's 30 years old, I expect it to last another 30 years at least.

My other bike is more of my good-weather fun bike, but since it's also capable of hauling stuff, I use it for quick pick-ups, long recreational rides, and to drop stuff off around town.

That one is a folding bike, so it stores and can be moved around more easily.