I have been generally involved in the advertising industry for over 20 years, initially as my primary profession and now more on the side. But what I've seen in that time is that advertising provides absolutely zero positives to the consumer.
This is a deep kettle of fish to be opening, but I don't believe that the world we have constructed around us is necessarily good for us.
And ultimately, while yes your examples are modern services that provide us convenience and entertainment, at a deeply human level I still argue that they are not providing net positives to us. Bread and circuses.
But on the other hand I'm almost certain I wouldn't have pushed through and gotten a degree without the internet (3b1b and Khan Academy in particular). I don't know what the world would look like without Google so almost impossible to argue, but I would definitely classify (ex. youtube) as "clearly useful".
Ad is the negative, and the services are the positive.