As with all things, there is nuance.
If the assumption that the metrics you are concerned with are privacy respecting, then that answers the question - if it respects privacy it’s fine. However, defining what respects privacy or not is really the hard part.
For me..
- Is it strictly internal for developing product? More acceptable.
- Is it sold to third parties for profit? Not acceptable for paid products, annoyingly part of a lot of “free” products, and I want to be able to opt out of this or I will find a way to block it.
Also keep in mind some metrics have little impact on privacy, some have greater impact, but it can be hard to tell what’s collected if not defined.
I think it’s largely best to evaluate on a case by case basis, and generally try to block by default when possible. If you really enjoy a service and trust + respect the company, consider enabling metrics to assist with their efforts and provide active feedback. Otherwise, it’s easier to play it safe than sorry.