Yes, but known 3rd party tracking cookies are already blocked. It's not like these tracking sites pop up every day, but the list is updated when new ones are found. Meanwhile, 3rd party cookies for legitimate uses are allowed.
Whereas Google just blocked them all with no regard to their purpose.
You can also choose to block all 3rd party cookies in Firefox, although it might break certain sites. And you can also keep 3rd party cookies (that are more functional than tracking) but maintain a different copy for each website so they aren't effective at tracking you.