In theory there are three ways Trump could be pardoned: by a state executive, by the current president or by himself. But the first and last ways there are somewhat complex in law. But not impossible.
Given the precedent set by President Gerald Ford’s pardon of a disgraced former president, Richard Nixon, there will be considerable pressure on Biden to do so. And given the nearly ubiquitous attacks on Manhattan district attorney Alvin Bragg’s indictment decision, it’s fair to assume that such pardon pressure would come from both the right and the left.
Trump potentially faces multiple court cases but to be found guilty each one needs to be a unanimous decision by all jurors. He only needs 1 in each case to find him not guilty and basically he wins.
Sending a former president to federal prison would be a first in US history, split an already split/polorairsed country and more than likely lead to killings by loyal Trump gun toting militia units around the country. Again, Biden would be under enormous pressure to pardon him if prison looks likely.
You could argue on a similar footing that Berlusconi and Sarkozy should have gone to prison for some of their crimes but in reality, while not pardoned they did their detention at home wearing a dog collar.