Stacked Bar Chart Customize Data Label

It would be nice if you could show an X Axis in $$ and then have the percent of total as the Y label inside the stacked chart. At least give the option to have more that just $$ as the data label as many online have tried several hacks and none of them actually look good or match up correctly. If you can do a % of total in a pie chart why can't you do it in a stacked bar - even with a % of total measure- why can't you make that the data label?