Crippling that is crippling their own bottom line and they know that all too well.
Apple will lose all incentive to makes sure their products last since their profit will come from selling new phones only - just like Android phone makers; right now Apple would rather you keep using an old iPhone and continue to give them money via the App Store than risk you switching to another brand and losing all revenue from you.
I quite like my phones lasting a long time - also more electronic waste isn’t good for anyone.
Frankly, I hope that they will decide to take the cut to their revenue and continue to operate the store at a lower profit, maybe even reducing the „tax“ to 10% across the board. This will be a hit to the shareholders, but who cares (I say it as a shareholder) at it will ensure that the ecosystem stays healthy. Apple should take this as an opportunity to improve the App Store instead of resting on their laurels. Also, I think the growth of the Mac business will more than offset the loss of the App Store revenue.