Agreed- solving tactic puzzles is a scam. Bigtime.
You can improve your chess a lot more by eating jellybeans. GM status guaranteed.
Are you sure that you are born in Greece? Because evidently there is no connection with the great philosophers of the past, the one which created skepticism. The OP had a skeptical question, most of the people here are making fun of him, without bringing anything real to support their opinion, apart a bunch of anecdotal evidence.
I do understand the other bunch of patzers, supporting the idea of tactic training, because evidently they would have done the same also in school. Not having enough brain to do anything else, but repeat as parrots.
However, since we should live in a scientific age, and skepticism is the way to think, let me ask you this: could you mention the tactic puzzle book used for learning by: Morphy, Steinitz, Lasker, Chigorin, Rubinstein, etc?
Of course we all know that Fischer had a computer which connected him to chess.com and played tactics all day long on TT.
Maybe if some of those school coaches would like to make an experiment, it would be interesting to try two different groups of players, one studying tactics, and the other studying only endgames, and see how they fare in tournaments. Maybe we could discover that those studying endgames are better and stronger players, showing that studying tactics is a waste of time (ops, am I plagiarising Capablanca?).
Please God save me from those who don't have doubts, and believe to know the truth.
TT is great but quite a few of them are incorrect. Much more than on chess tempo etc..