No president is an expert in every area. Good presidents seek out quallified, ethical, and compassionate Cabinet officials to advise them and run their departments well.
So let's go for a big stretch, and assume that Biden, who has 47 years of government experience and exhibits a good command of the facts in his speeches, and Trump, who doesn't read, attend briefings, or pay any attention whatsoever to facts, are "equal" in knowledge.
Trump picks a cabinet filled with former lobbyists, including an EPA secretary who was chosen because when he was running the EPA in his own state filed a lawsuit against the agency he was chosen to direct! He chose two department heads, Betsy DeVos and DeJoy, because of huge campaign contributions. He chose Wilbur Ross, who, as president of the Bank of Cyprus, was a Russian money launderer, as Secretary of Labor. He chose William Barr to protect him against all rightful and just investigations--and to go on witch hunts to hurt his "enemies." And so Trump is totally unschooled and egocentric in regards to national policy, and all his cabinet members are incompetent, corrupt, or both.
I know that Biden will choose a Cabinet wisely. I hope he would choose Susan Rice to be Secretary of State. The military respects him and knows he holds them in the highest respect. No general would ever kneel in desperate prayer in the National Cathedral, as Mattis prayed over Trump, because he feared that someday the military would have to take action to have him removed. Several generals signed on to work with him because they feared the country would fall apart if they didn't, but when faced with his obstinate irrationality and dishonesty realized there was nothing they could do--except pray about when it might be necessary to take action to remove him.
So if Biden has a good Cabinet, and listens and studies before making decisions, we will do fine.