The current ecosystem is overly focused on manipulation and there are simply to many ads, yes, but I have found really good products via ads and I don't think companies should be generally demonized just for playing the game. It's not all bad.
That's where we disagree. Imagine you always cooked your noodles in a pan. This is clearly a suboptimal situation. Then you see an ad for a pot, you go buy it and it turns out that making noodles (and other dishes) could be so much easier!
Sure, you would not have bought a pot otherwise, but this ad would have been a net positive for you and the ad company, no downsides.
Or maybe you see an ad for a Chinese restaurant, so you try it and it turns out you really like them. There's nothing inherently wrong with their food just because you got to know it via an ad.
As stated above, the current system is stupid. But it's not all bad.
The claim you're responding to is not that they won't allow it to influence their decisions, but that they will actively refuse to even consider a product if they learned about it through an ad.
Most of the ads I encounter are through podcasts because I don't watch TV and ad blockers of various kinds apply everywhere else. I will never use or recommend Squarespace for any purpose, simply on principle.