Cuándo usar un Stacked Column Chart
Your categories are time periods
Quarters, months, years. Columns run along the horizontal axis in the direction readers already read time, which makes a trend in the total obvious without a second chart.
The total matters as much as the breakdown
Revenue by quarter split by contract type, headcount by year split by department. If your reader needs both the total and what it is made of, stacking gives them both at once.
You have a small number of segments
Two to five segments per column stay readable. Beyond that the middle bands get thin, the colours get hard to tell apart, and the chart stops being useful.
Your category labels are short
Column charts give each label the width of one column. "Q1" and "2026" fit comfortably; "Marketing and Communications" does not, and that is when you switch to a horizontal stacked bar chart instead.