Why would there be any significant added cost to consumer good pricing?
Assuming ad tech makes advertising more effective, banning it would make challenging a market incumbent more difficult. You'd need to burn more cash to teach more consumers about your product, a larger fraction of whom would be outside your target market.
Granted, ad tech does not always add value. And there is a legitimate question as to the trade-off between privacy and consumer prices. But the tradeoff exists. Reducing the threat of new entrants means incumbents will raise prices.
An intermediary doesn't need to know me so they can profit from selling my existence and desires to a 3rd party at the drop of a hat.
No, it doesn't. If you have three pipelines between points A and B, removing one of them will raise downstream prices. It doesn't matter that there are two others. Removing an option will increase the cost of the others, even assuming equal effectiveness.
This assumes "ad tech" == "internet wide surveillance". That is certainly the most profitable subset, but it is still just a subset. Something needs to serve those ads and make sure they are relevant to the content they are shown with, even if it exclusively uses the context of the specific page being loaded. Something needs to manage campaign tracking to know which specific sites or which specific ad copy is driving users in, even if no information about the users themselves is captured. Something needs to manage the connections between the ad copy and the site being advertised, both to ensure users go to the place they are supposed to and to combat malicious or hijacked ads.
All of this is "ad tech". Even if you think we should return exclusively to the days of random, untracked banner ads some amount of ad tech is necessary.
I don’t buy many of the “costs will be passed on to consumers” arguments against regulation. If you assume companies already price things efficiently to maximize profit, then they cannot raise prices any further and make more money.
By your argument, taxing a transaction in a market would not ever raise the price charged to the demand side. It's pretty easy to see by reading a chapter about tax incidence (which is different from where the tax is legally placed) and elasticities of supply/demand curves that this is definitely false (not just in theory, but also in practice)
A similar argument could apply to cut the entire advertising industry down to mail-order catalogs and trade shows, which is something I'd like to see happening.
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[0] - Except the Sentinelese, I guess.
That doesn't seem obvious to me. Why would it not make it more difficult for the incumbents relative to the upstarts?
Users that already pay for these services for this exact reason shouldn't be impacted, but it will impact other services that people consider "free", I would imagine.