Tim Kendall has been an outspoken critic for a long time and also a recent central figure in the movie "The Social Dilemma" which is the about the same thing and will lead to more speaking engagements on the topic.
That doesn't dilute the message. If you think it does, what does a better arbiter of this aspect of reality look like? Who would that person be and what would their credentials be?
Honest question: Were they outspoken when they were a director at FB, or when they were president at pinterest? Or did it start two years ago when they became CEO of Moment selling an app to cut down on screen time?
In my mind, an ideal arbiter isn't also selling a product to fix the problem they are raising awareness about.
This doesn't mean what they are saying isn't true, or that they didn't have a real change of heart, but is certainly a conflict of interests.