Profiling is how you find out that the country field contains 47 distinct spellings of "United Kingdom", that 8% of the birth dates are 01/01/1900, and that a column documented as mandatory is empty in a third of rows. It is the cheapest diagnostic in data work and the one most often skipped, because it produces uncomfortable facts before a project has agreed on its scope.
In practice. Profile before you promise. Half a day of profiling on the tables behind a proposed dashboard will tell you whether the dashboard is a two-week job or a two-quarter one, and that is the single most useful thing you can know at the start.
Where it goes wrong. Profiling output is presented raw. Nobody outside the data team has an opinion about a cardinality report. Translate it: "the customer table has 14,000 duplicate records, which is why the churn rate in the board pack is overstated by roughly four points." Same finding, different consequence.