This isn't particularly new information, other than the IRS have formally contracted with ChainAnalysis.
THe IRS have not 'broken' anything.
They make it sound as if they've hacked Bitcoin, it's click bait.

The FBI were busting people using SilkRoad back in 2014 and tracked drug dealers via bitcoin transaction history.

Of course if you use an Exchange you give up identifying information to them.

Your public key/address is visible and the blockchain is public information.
If you are looking for greater anonymity then you need to employ additional techniques.