What term/theory describes more efficient utilization of a resource?
At the abstract level, this phenomenon is covered by the concept of "Technological Change", which, in Economics, does not have a strict/narrow "Engineering" interpretation: here, "Technology" is not only "how things are done" but also "how things are organized", and includes also new business models like the one you mentioned (see also this post).  

So the phenomenon is already embedded in the logic of economic models.  

Stochastic Frontier Analysis (SFA) and Data Envelopment Analysis (DEA), are two sub-fields focusing on modeling and measuring the degree of efficiency (under various interpretations of the term), in the use of factors of production at the micro-level.  

It is my impression though that since the examples you describe are relatively new, we still do not have enough data available to subject them to econometric analysis, so I cannot say if there are already papers that examine them (in a quantitative way).