Scalability Principle

Scalability is the proportional increase in some aspect of performance as more hardware is employed. Bitcoin transaction throughput is perfectly non-scalable as no amount of hardware increases it.

The block size limit consensus rule establishes the arbitrary trade-off between utility and system security. At any block size the system remains non-scalable due to the necessity of confirmation finality. In other words, a finite set of transactions must be selected, which implies that others may be excluded, necessitating a competitive market for inclusion. This market also finances confirmation security in proportion to demand for the money.

Effective transaction carrying capacity, and therefore aggregate demand, can be increased through the use of layering. This represents a local and time-limited security compromise, in contrast to the system-wide and persistent security compromise that results from increasing block size. Either compromise lowers but does not eliminate the utility threshold.

As such stability and non-scalability exist at any block size and level of layering.