You need decently large populations of risk takers living in reasonably close proximity to create an environment like silicon valley. There are plenty of places that have low cost of living, but as soon as you create that environment, the costs of living will skyrocket. Further, while costs may be lower than is SF, costs are rising nearly everywhere faster than inflation. For example in Cleveland the median home price was a mere $18k in 2008, in 2016 it was $40k, it's currently $110k. Buffalo went from $95k in 2016 to $180k now, hartford from $100k to $190k, and atlanta from $200k to $350k. Cost of living is of course more complicated than just median home price but you get the idea.

Nitpick: 2008 after the worst housing crisis in generations is not a reasonable baseline, that is the floor.

2016 is the baseline in my comment. In Cleveland the median home price increased by 122% in the 8 years from 2008 to 2016, then increased 175% in the past 4 years.