Scott Adams is the creator of Dilbert, a master persuader (or at least someone skilled in hypnosis and the theories of persuading), a writer, blogger, inspirational speaker, and the guy that predicted Trump would be President the soonest and loudest. (Not because he's a pure fan, as the ignoratti might claim, but because he's analytical and cynical).
Scott gets some things wrong, and some things right, and I certainly don't agree with everything he says (just most): but he's an observer of human nature who has insights that should at least be considered. So definitely not a waste of time.
"Win Bigly" is hit or miss. It's very interesting/enlightening on analyzing how persuasion of the public (or individuals) works: a fairly cynical analysis of humans willingness to gobble down confirmation bias. (From a mile high view). And he touches on negotiations. Scott had predicted Trump would win early (based on his powers of persuasion) and he explains why. He's not necessarily a fan of Trump... (he voted left in most prior elections)... but this book is filled with where he thinks Trump is dead on-target with some of his distractions and persuasion efforts, and that can be a hard read for some (even if the point is about persuasion, not likability/morality/positions).
His "How to fail at almost everything and win big" was quite good. It talked about overcoming adversity (his focal dystonia and spasmodic dysphonia)... and his ideas of implementing systems for improvement, instead of just goals. It's sort of an autobiographical self-help book, with an enjoyably rambling story-telling style.