I don’t think “too liberal” is accurate. George Gascon, his predecessor, was also a progressive. Chesa wasn’t elected by majority, but I think most San Franciscans - and most Democrats - would agree that mass incarceration has failed and we should seek evidenced-based ways to reform the criminal justice system. In practice, when the pandemic hit property theft spiked, and frustrations about the homeless situation came to a boil as criminals could break into garages or steal from Walgreens with impunity.
Quite simply, Chesa sucked at his job. I could go on at length, but the recall was the culmination of the manifestation of voter frustration with the performative politics of progressives during the pandemic. In a span of six months, we recalled three members of the school board following a series of national embarrassments, shot down Chesa’s former chief of staff for state assembly in favor of a YIMBY, and finally gave Chesa the boot himself - all overwhelmingly. To be clear, “progressives” are a distinct group within the factionalism of San Francisco politics, and San Franciscans are generally annoyed with city leadership as a whole, but they have generated the most visible controversies.
As for Chesa himself, I think Annie Lowrey summed it up best in the Atlantic: