Someone shared this with me earlier today, funny enough [1]. They track you quite thoroughly and link the collected data, including browsing history, to your identity. It's actually much worse than just browsing data, though [2].
Chrome does a lot of tracking. This seems obvious enough that I would reply by asking: do you have a source demonstrating that it does not track?
However there are many many many sources out there documenting Chrome's comprehensive tracking:
- Google's own ToS is probably too long to read, but it lists ways in which you consent to be tracked by the browser
- Google's proposals to the W3C for adding new ad-tracking tech to web standards go into detail on Chrome's own mechanisms for doing this tracking as a PoC example [0]
- Chrome isn't technically available on iOS; they are forced to use Safari's engine under the hood of iOS Chrome, which restricts in some ways the amount of tracking the browser can do. Despite this, the list of data tracked by iOS Chrome is listed on the AppStore download page and IT IS LONG.
Finally, you mention packet sniffing. In actual fact, direct packet sniffing has been made non-trivial by cert-pinning. This doesn't however prevent checking the frequency and destination of app phone-home requests, and yes, Chrome does it a lot. You can see this yourself if you use common user firewall tools such as LittleSnitch/LuLu/OpenSnitch/etc.
Ok it looks like you're right that by default a lot of tracking is done.
However the link you provided shows that in "Google Activity Controls" and "Google Ad Settings" the user has the possibility to completely opt-out of this tracking.
If privacy-minded users are fully aware of all of these options, that may be fine for them? (spoiler: I was NOT aware of all!)
The link provides (pretty convoluted) details on how to opt out of one very specific type of tracking that Chrome does.
There are other options in Chrome's settings that may allow you to further opt out of other types of tracking, if you can discover them.
These settings aren't documented simply or centrally by Google and can change with each release (releases are extremely frequent).
Then there are types of tracking that can't be disabled as Google classifies them as "legitimate interest" or required for certain functions of the browser (one particular example here that comes up often is the collection of wifi ssid data for geo apis).
Anything that's on by default will always be unmanageable even by most technical users. We need a browser that doesn't track by default. Otherwise, you must typically assume you are being tracked (this goes for Firefox as well, though I think we can at least assume less data is tracked in firefox and is slightly easier to opt out)
In the event that such behavior would occur, it can be detected by sniffing your packets, and people would very soon speak about it.