Hahaha. The solution described works if you have t=6. Try having t>>25.
The perfect use case for stacked area charts (but not pinned to 100%) is when there are many categories, but one is very predominant, and you're interested in (a) the sum of all quantities and (b) the participation of the principal category.
Example: a country is mainly reliant on hydropower for domestic electricity; there are years where it doesn't need any other source (it's still cheapest....). So we want to track (1) the evolution of domestic consumption and (2) the share of hydropower (3) which years it hasn't been enough.
The perfect use case for stacked area charts (but not pinned to 100%) is when there are many categories, but one is very predominant, and you're interested in (a) the sum of all quantities and (b) the participation of the principal category.
Example: a country is mainly reliant on hydropower for domestic electricity; there are years where it doesn't need any other source (it's still cheapest....). So we want to track (1) the evolution of domestic consumption and (2) the share of hydropower (3) which years it hasn't been enough.