accessor = undefined slows down the table

Question

I use react-table v7. During the table layout process, I noticed that the component rendering speed drops if the accessor returns undefined. For example.

const data = {
  person: {
    name: 'Ann',
    age: 12,
  },
};

const columnFast = [
  {
    Header: 'Name',
    Cell: ({ value }) => <p>{value}</p>,
    minWidth: 150,
    Filter: DefaultColumnFilterArray,
    accessor: 'person.name',
  },
];

const columnSlowly = [
  {
    Header: 'height',
    Cell: ({ value }) => <p>{value ? value : 'no height'}</p>,
    minWidth: 150,
    Filter: DefaultColumnFilterArray,
    accessor: 'person.height',
  },
];

The example is far-fetched, but it reflects the essence of the problem. Tell me what is the reason for the slowdown of the table in this case.