This is not what I mean.
There is no data layred.
There is no tracking every single click. It is possible to do that via tag manager and then using google Analytics.
You can track e.g.
Guest - someone who is not registered
Customer - someone who is registered and logged
When guest click to add a product you see that.
You can see which product and where has been clicked, where customer exit the shop.
You can then check if there are any problem with some group of customers, OS, or devices. (e.g there is new browser and there is some problem with shop).
You can then watch customers using e.g https://metrica.yandex.com/
to find a problem and fix them.
The same you can do with customers, see what customer add to card and when customer exit, leave the card.
Then watch and determine what is the problem and what need to be fixed.