It's one thing where a business is using data you provide them to make better decisions, just like a store would use sales numbers to decide how much of an item they should stock up.

The problem here is when data is collected by third-parties I do not know, do not trust, and do not need. They collect data for their benefit without providing me anything of value, only ads aka spam.

Online ads are also nothing like print or TV ads. The latter has a barrier to entry and some minimum criteria they must meet like the laws on what's allowed to be broadcasted and they are at the discretion of the publisher. This makes it less likely that a scam or malware would be promoted for example. Online? It's the Wild West, anyone can advertise anything (fake tech support numbers for example) for a few hundred bucks and targeting means they can make sure only the people most likely to fall for the scam would see the ad, while flying under the radar of anyone savvy enough to recognise it as a scam and report it.