Not saying this is a good thing, but this is Google’s entire business model. They are an advertising empire, and over the decades they’ve bought up and consolidated a bunch of smaller ad companies (like DoubleClick and AdMeld) into a giant advertising network-of-networks that tracks you all across the Web, Android, Chrome, Google Maps, Google Home, etc. That isn’t an accident, but by design. They give you all this free shit in order to track you and sell your time to advertisers.
Being able to sell ads on YouTube based on a user’s browsing history is just one of the many, many, MANY intrusive advertising services they offer: from About targeting for Video campaigns - YouTube Help (emphasis mine):
Your data segments: Reach more viewers across YouTube and Google video partners based on their past interactions with your videos, video ads, or YouTube channel after linking your YouTube channel to your Google Ads account. You can also show ads to people who’ve interacted with your website or mobile app.
That’s Google’s whole “deal with the devil” with all of its users, except those who pay for YouTube Premium (even they still get tracked, they just don’t see ads on YouTube itself… but their behavior still influences the ads they see elsewhere).
The old adage applies here: If you’re not paying for the service, you’re the product, not the customer. Google makes money from their advertisers, not from you, and you’re just an “eyeball” to sell as “clicks”.
Chrome is only getting more intrusive and track-y over time, especially after 1) the antitrust lawsuit against Google did nothing; it wasn’t even a slap on the wrist for them and 2) Google is increasingly desperate because of AI competition threatening their ad empire and 3) they know they have a browser monopoly and control the majority of the web.
If ya don’t like it, luckily a good ad blocker can take care of most of that for you. Brave has one built-in, but Brave is still built on Chromium (which is a Google product, the same underlying component of Chrome), so it’s still affected by Google’s decisions. Firefox for now has better ad blocking (uBlock Origin, not the “Lite” version), which can do a more thorough job, especially if you turn on all the privacy-related filters. Unfortunately, Firefox is almost entirely funded by Google as well. Edge is also Chromium. Basically the entire web is Google unless you use Apple products (which have their own ad networks). So unless you’re willing to de-Google-ify yourself entirely (there are a lot of websites and videos discussing how to do that), they WILL track you everywhere, all the time. You won’t have any privacy, but at least you don’t have to see their annoying ads if you either pay for YouTube or just get a good ad blocker.
If you’re using another ad blocker, you should be able to add the EasyPrivacy list to it (if it’s not already there): https://easylist.to/