Water is an enemy without the best gutter protector installed on your home. Presuming your roofing is not leaking you want to make sure that all the rainwater that runs down the roof does not have a chance of getting into your windows, siding, and basement.
Ideally, if you have a large overhang of about two feet and the ground around your foundation is sloped away from the foundation, and have a bed of decorative rocks all around your home, you really don't need gutters. The rocks simply disperse the water falling from your roof.
With a two-foot overhang, water will rarely be blown onto your windows and siding. The rocks won't erode like would happen with grass or mulch but instead serve to distribute the rainwater. You can also use the best gutter protection for your home.
The good news is that rainwater will flow away from the foundation since the ground is sloped away from the foundation. If you're designing a new home, this is an ideal design.
Unfortunately, not everyone is this lucky. Most homes have an overhang of a foot at most meaning that it's easy for any water from the roof to be blown back to the siding and windows. Similarly, it's unlikely that you'll find a home with a bed of decorative rocks around its perimeter with the ground sloped away from the foundation.
Without a large overhang, rocks around the perimeter, and the ground sloped away from the foundation, you'll need gutters to collect the rainwater from the roof.
If you have no trees around your home, you simply need to make sure your gutter installation is a quality one with effective sealing of joints at end caps and inside or outside corners. Likewise, you'll need to make sure that the downspouts lead the water away from your foundation and are unobstructed.