There are plenty of examples of nice places that remain nice even as people move in. It's up to the city to be dynamic enough to adapt to a changing environment

There are plenty of examples of nice places that remain nice even as people move in. It's up to the city to be dynamic enough to adapt to a changing environment. In concrete terms, that means: building sufficient housing and infrastructure to keep life affordable and smooth; designing (or shepherding emergent patterns of) functional, livable neighborhoods; and addressing social problems as they arise. You might be surprised to find that you can still get a studio in Tokyo within 45 minutes of the city center for ~$400/mo (bump up to ~$600 if you want to be 15 minutes away), that it's easy and efficient to get around to nice urban and natural amenities, and that there are endless quiet, peaceful, and utterly charming neighborhoods, parks, and temples right next to all the hotspots. You'll never see any feces on the street, you never see anybody shooting up needles, and nobody will ever beg you to spare a dollar. Part of that is cultural, but most of that is by concerted effort. But positive outcomes like that can only happen if a city successfully adapts to changes—which San Francisco (and virtually every American city to varying degrees) has abysmally failed at. As another commenter pointed out up the page, San Francisco's public policy has been very nativist, and the physical form of the city has remained more or less unchanged for decades, which spells disaster for one of the most coveted places to move to in the world.