I wouldn't call that meaningless privacy theater. For one, you can buy a SIM anonymously, and make the cell location data essentially useless. Second, protection at the DNS level prevents other types of data exfiltration (such as cross-site tracking by the Meta Pixel). By not using social media and communicating over secure apps like Signal, you can indeed achieve a high degree of resistance against tracking and profiling.

Of course, you can do more, such as running only trusted software (i.e., free software) on your devices, not using Internet-of-Shit devices anywhere in your home, and making sure your car is not snooping on you through it's own cellular modem.

> you can buy a SIM anonymously, and make the cell location data essentially useless

Even ignoring the first part, which will vary by country, I think that represents a failure of imagination.

For example, how many other people-with-phones have a pattern of spending 5+ nighttime hours within 100m of your home, and spending 5+ workday hours within 100m of your office?