Language is complex and nuanced. Identity theft is an interesting edge case - your identity is an intangible, but it's also not something that someone else can use without harming you. They're effectively stealing your reputation. It's not a physical thing, but especially in the age of digital tracking, there's only one instance of it.

Regardless of the linguistic semantics, the campaign to conflate piracy and stealing was a manipulative mind game that tried to dissuade people from a common activity by overstating its harms. Pirating a movie is victimless, except for aggregated market effects where too much piracy can impact the financial viability of film production. It's very different than stealing, which has a discrete victim.

If you download a movie or a game without authorization, that's a societal no-op, unless it's a thing you would have paid money for. At scale, pirates do include people who would have paid, which is problematic for the film business. That's bad and worth solving, but it's not the same as stealing.

Not a great analogy given fixed space on a bus or a train; in rush hours a fare evader occupies a seat that would otherwise be occupied by a a fare payer (presumably).

Media piracy is largely associated with either people that were never going to pay for a cinema seat or DVD, OR (and this is key) people that would likely pay for something were it available ...

I assume you mean "fare" evasion -- like riding a train or bus?

Yes, it fits. There are a finite number of seats on the train, and your gratis use of a seat (ostensibly) denies another paying customer. Even if there's excess capacity at the time of your ridership, the train operator is designing their capacity with buffer, so you're essentially stealing the capacity.

You could just as easily peg the theft to the incremental cost (electricity, gasoline, etc) it takes the train operator requires to move your incremental mass from A to B.

This is distinctly different from infinite, free copying & distribution.