The orbits are designed to maximize coverage; it's clearer if you look at the orbital parameters instead of a globe, where you can see that satellites are evenly spaced: https://imgur.com/a/aReh0EQ The details are complicated, but each satellite can see quite a large area and any given spot on the ground is within range of 3-4 satellites.
That's not what that chart shows. The satellites are not evenly spaced over the globe. Most of the satellites are in 53 degree inclination orbits: those orbits have zero coverage at greater than 53 degrees latitude, and they have non-uniform coverage of smaller latitudes. (To see this, consider a constellation of 90 degree inclination polar orbits: the poles clearly have a higher density of satellites than the equator. Similar is true for lower-inclination orbits, albeit to a less extreme degree.)
those orbits have zero coverage at greater than 53 degrees latitude
That's not actually true -- the horizon distance at those altitudes is several thousand km, and one degree of latitude is about 100km, so the satellites are actually visible quite far to the north of there. Of course, they'll be increasingly far away and close to the horizon, so not optimal for reception.
