So yes. They are knowing more about us than we know even of ourselves and yes, all that you mentioned is just it. Just it!
Some say they use to influence even election decision-making. With that much information about us, on a general level, they can influence anything. That high frequency thing you mentioned is very possible really. With google especially, they have that much power, looks like they rule the internet. I still use their browser alot though and ofcourse gmail, youtube etc, so how won't they know so much