Are there situations when it would make more sense for me to sue a defaulting tenant for breach of contract, instead of evicting them for non-payment of rent in San Francisco or Oakland?

Yes, there are situations when an owner may opt to sue a tenant for a breach of contract rather than pursue an eviction. For example, in San Francisco, Proposition F gives tenants facing an eviction the right to a free attorney. If the owner decides to sue a tenant for breach of contract, the tenant may not receive that free legal help because they are not facing an eviction.