Apple doesn't currently get 30% of every subscription I use on my iPhone, MacBook Pro, iPad, and/or AppleTV. I have Amazon Prime, Netflix, Disney+, Peacock (temp for the olympics), etc.... Apple gets no portion of those subscription services so far as I know.
Now, if I purchased those subscriptions through a "Samsung Store"/"Sony Store" or Amazon/Walmart/Target/Publix, whatever then some percentage or possibly a flat fee would be be appropriate for the "store" to get. I have no problem with this, the world has a rich history of paying facilitators and middle men. I'm happy to do it when they provide value and I accept doing it when they don't add value.
I'll concede that 0/15/30 may not be the correct values. But the entire "App" industry is relatively new and like any new market it takes time for equilibrium to develop and for business models to adjust. It is possible that 0/15/30 made since at the emergence of the market and now maybe it doesn't. That is something that should be worked out between developers, companies, and customers, not legislators (IMO). I think it is safe to say that the least qualified person to provide a meaningful solution to any of these questions is a politician.