JQA is the most conspicuous outlier, because he did quite a bit. However, as I pointed out, 8 years in the Senate and 4 in the Cabinet is pretty typical for a presidential contender.

Al Gore, for example, had 8 years in the Senate, 8 years in the House, and 8 years as VP.

John Kerry, John McCain, and Bernie Sanders all had lengthy Congressional careers before becoming candidates.

The only way to consider Hillary Clinton above average in her qualifications as a presidential candidate is to give real weight to being Bill Clinton's wife. (At that point, we may as well credit Bush II for being the son of Bush I, etc. The Clintons are not the only political family to emerge in the US.)