You can verify everything you DASHTARD. I can even prove i send amount XY to account ZZ.
That is called cryptography, also u can count every fucking monero coin created in every fucking coinbase transaction.
ok, lets just define "verify" for posterity here.
"Verify" to me means that for a given transaction:
[1] - the originating address is publicly verifiable
[2] - the destination address is publicly verifiable
[3] - the transaction record is publicly verifiable
[4] - the debit balance movement on the originating address squares with the credit balance movement on the receiving address (or vica versa) and that both movements square with the publicly documented transaction amount
...and all that, not just for someone that I happen to give a "viewkey" to. For the whole damn universe to verify is they so see fit.