Communicating with someone isn't a crime

You said it. Neither metadata nor content. But both can be interpreted as evidence of a crime, and used as such in a court of law. And both very routinely are.

a real world example where the metadata is "more revealing" than the content of the message.

Since you are apparently interested in crime type examples, let's go with that. I message my drug supplier: "Hey dude, what's up. You want meet up at the place for that thing today?" Message is encrypted (of course) so police get just my phone number, which they use to get my real-world identity. They then use that to obtain geolocation data from my telco, follow my movements, get details of people I communicate with. One of them is arrested for drug possession. Cops say: We know that you know TheBrainSlug. He is a drug dealer. Buy a some drugs off of him and we drop the charges. Now serving a very long prison sentence. All started with a single phone number.

Now, this example was of a criminal, who we may not be sympathetic towards. But remember that exactly the same kinds of data are used all around the world against people like equal rights activists, democracy activists, "freedom fighters", etc. Think about my above example but replace the drug supplier with an exiled democracy activist and the police arranged drug deal with a conversation about politics over coffee. The result is the same. Indeed Michael Hayden, former director of both the CIA and the NSA, has very clearly stated: “We kill people based on metadata.”. And he meant it: targets for drone strikes are/were very literally being identified solely on the basis of telephone metatada (both information about numbers called/messaged and geolocation data), leading to thousands of deaths in Pakistan in particular.

You accuse me of spreading FUD. But this really is very serious stuff, and this data legitimately should cause many people in the world very serious concern, and even legitimate fear. I know that you simply don't recognise how this information is actually used buy, but please don't try to trivialise this issue until you spend some more time informing yourself.