"traffic to Stack Overflow has steadily dropped over time"
And that will continue in inverse relation with just how much Stack Overflow considers itself a money-making tool versus a public utility.
The more Stack orients itself towards making money and locking down its content, the less people will go to it.
Tek Tips is a site that has never changed its objective : being useful to the public. It has competent people in every one of its forums, and I have never had a bad experience on that site.
Stack, on the other hand, has form in restricting its content unless you pay, thereby declaring its basic intent. Stack is not my first choice destination to solve a problem I might have.