A mostly admirable, but uninspiring, elderly president is the victim of economic circumstances over which he had little control. The base had little use for him; it longed for someone who was more charismatic and fed them more red meat. His foreign policy successes were ignored during the campaign. A third-party candidate siphoned votes from him. History treated him kindly, but his contemporaries did not.
Yes, if you’re a Democrat, the historical analogy you should fear is 1992. The essential difference is obvious, however; Biden may resemble George H.W. Bush in some respects, but Trump is no Bill Clinton.