Where's the flaw? All those outputs are private.
There are 262 input and 294 output collaborators
That's called "remixing", those 262 inputs and 294 outputs gained even more privacy. It's not a flaw, it's an advantage, because someone trying to track the flow of someone's coins now have to consider inputs from previous transactions and spends from future transactions.
A mixer wouldn't provide you any privacy since they are a trusted third party, you would just end up having your coins stolen.
A mixer is a service with sole purpose to increase on-chain privacy. The required trust doesn't change that fact, nor do the instances of mixers which were either scams or were confiscated by the authorities.
You are wrong, a mixer is a trusted third party, they do not provide you privacy. The instances of mixers stealing their users confirm this fact, with the end result of having their users' transaction history given to government agencies:
https://bitcoinmagazine.com/technical/how-authorities-found-bitfinex-bitcoin