You don't say!
> absolutely nothing to improve the quality of purchasing decisions.
They do communicate the existence of competing products, and are basically the only way to compete with an entrenched market leader. In this sense, advertising is rather important to keep markets fluid and allow better products to flourish.
> rationally consider the direct marketing points you convey
For someone considering themselves hyper-rational, you comment shows a surprising amount of negative emotions.
It's also rather irrationally to believe one of the largest industries is consistently wrong by not following your preferred format of notarised feature comparison spreadsheets.
Because marketing is really full of spreadsheets: those showing that people do sometimes have emotions, and that appealing to them is good business and, frankly, not quite the end of the world.