Why is it better to display data in a bar chart rather than in a table?

The claim made in the question is not valid. A bar chart summarises data whereas a table is more likely to give more detailed information. So the choice between the two methods of presenting data depends on the purpose: a quick and easy impression or detailed figures.

Also, having worked as a professional statistician for over 30 years I have come across some people who can digest tabular information but cannot make head or tail of charts and there have been others who love charts but simply glaze over when presented with a table.

It is therefore important to bear in mind the purpose and the audience.