On Twitter, Wietse Wind explained the reason for the removal of a certain option.

On Twitter, Wietse Wind recently explained the reason for the removal of a certain option. He noted:
Just a few days ago, the option to spend XRP to buy Xumm Pro was removed by us from the @XummWallet Pro launch screen.
We had to do this as we didn’t comply with Apple’s in app purchase policy: allowing users to pay with XRP (which Apple doesn’t offer).
We appreciate Apple for their ecosystem and us being able to target our ~50% iOS users through their store.
We would pay a fee for Xumm Pro subscription purchases through Apple Pay, but: Apple doesn’t allow our users to pay with XRP.
So: remove in app purchase or no 2.4.0:
Our Xumm update was rejected because of it. It made us decide to remove the direct Pro purchase option.
Instead, you can now purchase Xumm Tangem cards (super secure NFC hardware wallet cards, and you’ll automatically get Pro in the process.