Because it’s literally the minimum wage. States are free to raise it higher if their cost of living is higher, but it makes sense for the federal government to say “there is nowhere in the country where you can support a family on less than this dollar amount so everyone should have to pay at least this”

And differences can be a magnitude apart living in different parts of the state! I live in a major east coast city, where a small rowhome in my neighborhood is 200k+ in good condition.

new houses in the state capitol 2 hours away? No problem coming in under 100K.

So COL varies wildy even within a state, as is no surprise.

I don't disagree, this is just making my point even more :) And reinforces the original comment that a minimum wage that doesn't take these disparities into account may simply be a death blow for a lot of small businesses in low CoL areas.