I have worked in countries where voters are easy to please. As a result, I had clients who would get approval ratings as high as 70%, 80% or even 90%. American voters, on the other hand, are definitely more cynical. In particular in recent times, it has become noteworthy when a nationwide politician crosses the bar of 50% approval rating. In the RCP average, Joe Biden's approval rating currently stands at more than 55%. An impressive result.
During the campaign, it was commonly said that Biden was an unappealing candidate. Commentators described him as too old and as lacking charisma. How come then that Joe Biden reaches such a good approval rating when he was such an uninspiring candidate? As a point of comparison, Donald Trump barely ever approached 50% approval during his entire presidency.
Let me answer the question by making an analogy to dating. What we are attracted to in the early stages of dating is not necessarily what makes us happy during a longtime relationship. In that sense, yes, the Biden campaign was not the start of a new youth movement, he himself did not deliver great speeches and his debate performance was mediocre at best. But now that he is in the White House, who cares? What matters now is totally different: presidents, prime ministers, governors and mayors usually get elected to do a specific thing. Let us call it the mandate. As long as voters think and feel that the guy they voted for is at least trying to deliver on that one issue, his or her approval rating usually remains intact. In other words, he or she does not have to solve all the problems over night, but has to be seen at least trying to deliver on the key promise.