When public transport is ubiquitous, the last mile is really just that, a mile, tops (in urban environments). The difference between public transit somewhere like Japan, where everything is linked and you have intermodal hubs efficiently connecting higher speed and lower speed transit and what we have in US cities is staggering. It's downright easy to cross the entire country in the span of a few hours, only stepping foot outside for the very short walk to the nearest metro. Then you usually just have metro -> shinkansen -> metro, all connected to eachother, to get to where you have to go. You might need to change your metro once, but that's hardly an inconvenience when the connections are in the same building and you just walk a few feet from one platform to the next.
Compare that to Seattle, where my friend got lost trying to get from the light rail to the incredibly slow train up to Vancouver because they're several blocks apart. And then had to do the same on the Vancouver end for the same reason. To make matters worse, the train between the two cities is actually slower than the train between Tokyo and Hiroshima, with roughly 3x the distance.