<source: did fancy things with logs over the last 25 years, including running multiple tools on the same site in parallel to do comparisons (Analog, AWStats Urchin, GA, Omniture, homegrown, etc...)>
For example, in the EU, you need user consent to use server logs that include IP addresses for analytics. You also need to provide post-consent opt-outs and privacy statements and audit logs and all off a sudden you're building another analytics tool.
Not a single line of tracking or analytics on the front end, we just tracked everything we cared about at the server level.
¹ To those who would say it doesn't matter, I'd say that laws aren't laws if they can't be enforced and there's no enforcement mechanism for some EU bureaucrat to fine a company with no operations outside of the US.
² I'm sure the technical means existed to do it especially if you already had access to the logs but the point is we weren't explicitly storing any PII or data that was linked to a real account. Just actions throughout the apps.
What I am trying to say is that you can still do analytics, even pretty advanced stuff with some more elaborate scripting, if you want. The only thing you need is the access log.
Something which has been largely forgotten ever since tools like Urchin became a thing :)