Yep, 100% of it. Please ignore the hill down the street from my house that two wheel drive cars often can't climb when snowy. It only has about 90 feet of elevation gain over about 2000 feet of distance. The steepest section is about 10% grade over 600 feet. No problem for a typical person riding a cargo bike without electric assist.
Note that the maximum grade for a wheelchair ramp is 8.3%.
I'm pretty sure 10% was what i had in Limberg. Can we agree that both midwset and netherland are generally flat, and while there are hills in both places, this isn't San Francisco?
By the way, i visited Chicago, Michigan and Colombus, Ohio: I might now have seen everywhere, but those are closer in elevation difference to Amsterdam than Paris and Lisbon are
Aside from the hilly areas of San Francisco, it is quite flat too. Whenever I've visited SF my primary mode of transit is walking. Except for the time I stayed in a hotel at the top of Nob Hill, I was generally walking on land that is flatter than that found in my neighborhood and the older parts of the UW Madison campus.
From what I recall of Columbus, it is every bit as flat as you say. I'd have a hard time telling you about a hill in Chicago. Then again, I'd have a hard time telling you about a time that I was on something other than an 6+ lane highway in Chicago. The view you get from a major highway is often different from what you get in areas where you think of your kids having a casual bike ride.
Note that the maximum grade for a wheelchair ramp is 8.3%.