The obvious answer to this is that it would make our power grids more efficient.
Such a superconductor would be an obvious natural replacement for copper in our electrical circuits. After the Maxwell equations are first discovered on such a world, electrical generation would still be in its infancy, but being able to use a naturally occurring superconductor in generator wiring (for example) may make those generators more efficient because they would heat up (through resistance in the wires) even less than they do now, and that means more electricity is available for the circuit.
In modern (?) sound systems, gold is often used for contacts and in audio cables because the superior conductivity of gold over copper means that you get a clearer signal transmitted. So, good quality sound may have appeared much earlier, and if there was enough of the material for industrial power transmission and distribution, it would mean that we get a lot more power into homes for less generation. In the end, the difference may only be marginal but in scalable applications like maglev trains, this may make them viable at an earlier stage of development.
It's also possible that naturally occurring superconductors may speed up nuclear research, particularly in the space of fusion reactions given that superconducters are an integral component of the magnetic containment systems used in fusion research today.
If we are getting really speculative, it could have also revolutionised the work that Nicola Tesla was doing in wireless power transmission; even if wireless transmission proved inefficient by comparison to superconductor wires, having the power feed into a superconducting circuit would also mean that the amount of power that had to be received would have been lower for the same result, making it more viable as well.
Computers may have benefited also from being able to feed a proportionally lower volume of current into the chip because one doesn't have to account for resistance in feeding the circuit. This may have made it possible for Moore's Law to work in (say) 12 months instead of 18, at least for a time.
Of course, all this is dependent on the usefulness of the material in terms of flexibility, malleability et al. The one advantage of copper in that regard is its ability to withstand being bent and flexed; a brittle superconductor may not be as useful in things like power cords, so the physical attributes of the superconductor would also play a significant factor in its relative usefulness.
That said, a naturally occurring, flexible room temperature superconductor available in quantities similar to copper would have been extremely useful in a post-Maxwellian era.