Not necessarily. This is only true for companies where minimizing the cost is the best (sometimes only) strategy to increase profits. Tata, EDS, Accenture, and the many IT body shops are all in this camp.
For the so-called "SV tech companies", they need a steady supply of talents to continue creating products that in turn generate new revenue streams. This is much more valuable than saving 30% off in an individual's compensation -- at the expense of high turnover, when said worker realizes he/she is being underpaid.
Artificially reducing an already dwindling supply of talents in the top tech hubs won't make salaries go up; it will simply shift the jobs elsewhere. That is already happening for many companies.