Google might require that non-custodial wallets collect the user's email address - and verify that it's a real address. So not full KYC with passport photos and so on. And over time, they might gradually make that stricter

So it’s ok to require full KYC by these gatekeepers for Custodial wallets like Wallet of Satoshi?

Im not saying its ok. But such is life. and if non-custodial arent affected, why would custodial?