I don't understand this analysis. Why are you showing "profit" as being equal to gross for some stakeholders (Composers, writers, performers), but as only 5% of gross for others (labels and platforms)? And, furthermore, what's up with "estimating" the profit margin at a single number, and then applying that same number to two very different operations (labels vs. platforms)? That looks quite strange.
The whole focus on "share of profit" in this scenario is one big misdirection. It is of no interest what profit record labels have if their cost level is out of control vs their income and value. The record labels need to seriously adapt their cost levels to a new reality. They've had an extreme golden age in the decades of the CD, but now reality is different, as it was before.