in monero every tx has to prove that
the sum of the inputs equals the sum of the outputs
to be accepted as valid.
and i dunno, sometimes things are not obvious even when values are transparent.
bugs can be sneaky.
also
bitcoiners make a big noise about auditability
but when was the last time you summed up the utxo set to confirm the supply?
even if people do anything at all its usually just run gettxsetoutinfo on their node. it's never that they build a little tool to do it themselves
point is,
bitcoiners are trusting others to confirm the supply for them too
its not that different than monero.