when an anonymous transaction is among a bunch of clear ones, it becomes easier to identify it. The IRS posted a reward for breaking Monero not Zcash (could be because the added features zcash implemented to comply with govs). For privacy and encryption related subjects, I believe one can only...
because it has a foundation taking a large cut, it isn't private by default, they have great tech but are assholes, bent a knee to anti anonymity gov measures, less than 1% of the dark web used it, suffered 51% attack, etc.