I have too, and I can too. Though one of those was a bank that turned out to be a showstopper; I have to flip the pref, then flip it back every time I interact with them. Not some thing I can ask "normal" users to do.
It also turns out that this varies a _lot_ based on browsing patterns. For example, I never use the "log in with Facebook/Google/etc" things. People who do report a lot more problems from blanket third-party cookie blocking.
It also turns out that this varies a _lot_ based on browsing patterns. For example, I never use the "log in with Facebook/Google/etc" things. People who do report a lot more problems from blanket third-party cookie blocking.