Trump never actually got above 50% in any live interview poll.
Biden, by comparison, has done it multiple times. He did it in the CNN/SSRS, Fox News and New York Times/Siena College polls in October, to name a few.
Unlike Trump, Biden’s favorable rating is now usually above his unfavorable rating. The national exit poll pegged him at a 52% favorable rating to 46% unfavorable rating, for example.
Biden’s favorable rating right now looks similar to Barack Obama’s heading into his second term in 2013.
This gives an insight: Biden being more popular than unpopular isn’t abnormal. What was abnormal was that Trump was elected, despite being so unpopular. Perhaps even more unusual is that he could never get above 50% during his presidency, which is unheard of in modern American politics.