When I forget to sign in to YouTube, I see the same pattern, shitty ads that are clearly only allowed because otherwise YouTube wouldn't have sufficient ad inventory to meet their internal KPIs.
Who buys pillows because of email spam and YouTube ads? I don't get it. It's probably not a scam, but a very obnoxious company nonetheless.
Some people are going to buy those pillows based on those ads. Others are going to think the ads are stupid but will remember the brand and are now more likely to choose it if they see it in a store. Ads persist because overall they work.