We have lived in the same house for 28 years, and quietness is a big reason for it.
The house was built by the original owner with lots of sound isolation - thick floors and walls, thick insulation, double pane windows, etc. My home office/man cave is in the basement, and it can be thunder storming and raining cats and dogs and I won't hear anything. Some times i am surprised when I go upstairs to notice that a heavy rain happened. Likewise, I can be watching an action movie full of explosions in the cave home theater, and on the main floor you might fell occasional vibrations on if you are in the room directly above. If you are on the 2nd floor you can't hear anything.
DW likes to play piano and other instruments, and likes that she can do that without disturbing anyone else. Even when she is playing piano in the living room, I can be on the same floor in the family room (which shares a wall) watching TV sports and neither of us will notice the other.
If you go outside on our porch or patio, if the sounds are not in the adjacent rooms you can't hear anything.
There are a couple of drawback, you cannot hear the doorbell when in the basement, or not directly above the door when on the 2nd floor, and we have to use an intercom when we are not on the same floor to get each others attention. But that is a small price to pay.
Our house and our neighbors each have between 1/2 and just over an acre of land, so the distance helps. 3 of our 4 neighbors have been same since we moved in and live relatively quiet lifestyles. The "worst' was one neighbors kids and our kids were the same age and became great friends, so it was either noisy in our house or noisy in their house. But the friendships they built were worth it.
Interestingly, all of our neighbors (and many others in the neighborhood) remarked at how much quieter things got after we moved in, even with our kids. Apparently the folks we bought from were known for public screaming fights (they had to sell the house due to getting divorced), and their teenage kids had frequent parties with kids running through neighbors properties and police having to be called almost every weekend. So our "noise" was like silence compared to that.
This will be a challenge when we decide we can no longer handle the house - finding something that not only is quiet, but where we can make our noise and not disturb others.