> There is nothing in the word “theft” that implies depriving someone of physical property.
Of course there is. It's origin is the crime of taking of tangible property owned by someone else without consent. It did not apply to intangible property because it predates any concept of legally protected intellectual property that can be duplicated without loss.
Now, there was also the metaphorical use of theft for non-criminal / non-tangible things but poetic use of language shouldn't be confused with primary meanings. For example, "plagiarism" comes from the Latin for "kidnapping" coined playfully by a comic. It was never a crime or ever resembled actual kidnapping. If you call your poem "my baby" because of how precious it is to you, it doesn't become one. Badly editing your poem is not murder either yet you might complain in such dramatic terms.
You might want to argue something about metaphors and secondary meanings but we shouldn't consider the crime of kidnapping to mean reciting other's verses any more than a summer's day should mean temperate people. If we start taking metaphorical uses literally then you also have to start claiming silly things like most kidnapping being legal.
Only in later industrial society did the metaphor become less metaphorical in written law for criminal acts that emerged post-printing-press that were being called fraud, deception, infringement and piracy.
> deprives the owner of privacy
It's pretty metaphorical to describe such things as property that can be stolen.
With this latitude you can frame every injury as theft e.g. stabbing is the theft of good health, murder is theft of life, perjury is theft of a fair trial etc. You might choose to use such language because it's how we roll, but we also know that, as offences, they are not theft.
When an item cannot be traded or restored to the owner, is it property that can be owned and stolen or are concepts of injury, damage and destruction more legitimate?
When it comes to intellectual property, it's closer to contract law where citizens are compelled to abide by contracts the state issues and enforces. The movement of intangible theft from metaphor into law for breaching such a contract was popularised by the beneficiaries to rhetorically inflate an illusion of loss and justify severe sanctions for acts not considered unlawful for most of human history.