Paris is not on a fault line either. Or built on large portions of land that suffer from liquid faction.

That isn't a credible argument. We've known how to engineer for seismic risks for a very long time and many dense, tall cities are built on top of faults in seismic risk zones at least as severe as San Francisco without issue.

For example, Tokyo and Seattle. San Francisco even has the advantage of being merely fault adjacent. In cases like Seattle, a major thrust fault runs through the city. It doesn't prevent dense construction.

SF like most American cities has suffered poor city planning and no foresight about future population growth.