Torque is physical characteristic of the engine (at the output axle). as is rpm, but as a 'number' it is only relevant WITH rpm, because 'torque' is simply the physical force of the engine at its output, which can be manipulated any way you want, with gear/levers.. hence it MUST be stated WITH rpm (as HP, or power) otherwise it it truly meaning less.
Why it SEEMS relevant, is because turbo engines give high torque at low rpm, which is the equivalent of high HP at low rpm (the two are identical). The same with diesel engines. So it is a characteristic of the physical setup (NA vs turbo, diesels) which give higher power at low rpm (=high 'torque' at low rpm).
That said, it is a misleading number, as it leads people to draw wrong conclusions - but it is given simply as a statistic of the engine, for engineers to use.
So if you want to talk about something that is accurate, you should talk about HP@rpm (=torque*rpm@rpm), or if you want to see how fast a car is, you also consider how fast it revs.