What's special about Germany, Austria and Switzerland that they don't get the user activity tracking?

I don't know but assume its a similar issue as with Google Analytics. In Germany, you are not allowed to use default configured Google Analytics. User IPs are PII for our data protection laws (it is possible for someone on earth to know who is probably behind that IP like telcos). As a consequence, we need to disable IP tracking:

https://developers.google.com/analytics/devguides/collection...

Really strict data privacy laws with a regulatory environment that doesn't play games and heavily leans towards consumer rights. In Germany at least, you're also required to obtain double opt-in and record extensive documentation of the entire opt-in process just for email marketing. If you overstep your bounds and draw the attention of regulators in Germany, it has all the comfort of the Eye of Sauron staring at you[2].

[1] https://blogs.oracle.com/marketingcloud/email-marketing-clar...

[2] Lord of the Rings reference. Most apt description I can think of for the dread that comes at the mere thought of pissing off German regulators in this area.

Enforced strict privacy laws.

Could be related to having a history of having to deal with mass surveillance, see stasi.

Laws that make this kind of tracking without explicit opt-in a crime. As it should be everywhere.

Their governments care about privacy.