Anyone who prevents these necessary analysis services with external tools because there are uncertainties regarding personal data can be reassured. Because the data that are collected are completely anonymized. A website operator could never say that, for example, Mr. / Mrs. XY visited the following pages on the day and the day. The data depth provided by analysis services such as Google Analytics go geographically down to the city level, and an estimate can be made as to whether it is a male or female visitor.
The fear that one will be identified and completely pursued here is therefore unfounded. The situation is somewhat different with tracking tools used by large tech groups and social media services. Because here you usually maintain a customer account in which a lot of personal data has been stored. It is actually possible for these pages to determine relatively precisely which user is on which website.
Following this, the marketing cookies, which are extremely important for such sites, are used.
You can also easily try it out yourself by calling up any page on which an advertisement for a product for which you have recently been interested appears, then simply delete the cookies in your browser and simply update the page again. You will then see that this ad has suddenly disappeared, and either none (rather unlikely) or a completely different advertisement appears, which may be less related to your interests and more related to the content of the page.
By the way, if you use the “Delete all cookies” function in your browser, you will also find that you have to log in to your Facebook account or your Amazon account and the like. Because login information is also stored in cookies so that you don’t have to log in again every time.