For example if I earn $500 from freelance work, but spend $200 on marketing and $400 on transport to do that, then a Sankey diagram like the one on the front page where everything gets intermingled in a main account and expenses get deducted at the end make it seem like this freelance work is a good thing and I should probably do more. In a good Sankey diagram I would immedately deduct the expenses from the freelance work, and see that instead of freelance income reaching my budget I'm actually subsidizing freelance work from my salary income.

Similarly in your example it's immediately obvious that if the wage would vanish a lot of the taxes would also vanish