"Class methods and useEffect are both things you could do another way or might not be advisable for particular circumstances" isn't a title that rolls off the tongue quite as nicely. ;-)
When I see useEffect, a little alarm goes off in my head telling me that it's worth exploring alternatives. I was hoping to give folks that same instinct for class methods. Didn't intend to imply that they performed similar functions, sorry if that's how you received it!