Why wouldn't you think this? There is no system in place for monitoring those companies, nor is there any type of punishment for if they were to be proven to be doing so. While on the other hand, there are piles of money to be made from advertisers for allowing exactly that to happen.
I've personally had things come up as being advertised to me after being NEAR people talking about those items, and I have seen several videos where people show this effect in action.
Frequency illusion is real, but is not reliable enough to repeat over and over, back to back, unlike the advertising.
When, ever, have the capitalist companies prioritized morality over money? Never.