Will often prove sufficient in many cases

Can you please explain the bolded part?When considering these scaling techniques, one could argue that size scalability is the least problematic from a technical point of view. In many cases, simply increasing the capacity of a machine will the save the day (at least temporarily and perhaps at significant costs). Geographical scalability is a much tougher problem as Mother Nature is getting in our way. Nevertheless, practice shows that combining distribution, replication, and caching techniques with different forms of consistency will often prove sufficient in many cases.

Distributed Systems, Tanenbaum