>Cookie banners aren't a requirement unless you wish to store cookies that aren't strictly necessary (statistics, marketing, etc)[0]. Cookies that are essential for the user to browse the site (login tokens) don't require consent.

So if I use telemetry to catch some dirty frontend blob throwing a hissy fit of an exception and that telemetry is tracking sessions rather than individual events (hello ms app insights) -- is that functional or, statistics or etc?

If you are monitoring the system but not its users, then that is not collecting PII.

To be completely sure, you should eliminate anything that might be considered PII.

So unadorned exception counts would be anonymous, aggregated statistics, which is fine. But exception counts reports per IP address, or per session, or where the exception text mentioned the user's PII, would require consent from the user you're tracking by processing that data about them.

If you heavily rely on performance marketing, your business model is anyway in trouble. In the past businesses survived with non-digital marketing channels just fine.