a lot of companies pay salaries agnostic to where you are. Or do very little adjustment. You can look at buffer's new pay system (it's all open). A lot of other remote company do the same or something pretty similar.
Google is one example. And AFAIK they don't support remote work. So they have offices in multiple countries, and usually pay a salary related to the local market.
Most big companies with offices around the world adjust their salaries to local market because it is yet another way to optimise, and with a physical location, it doesn't make sense not to level. It's also how they budgeted the office to decide if it's worth having or not.
So salaries in most locales will be way closer to the market. I moved myself from SF to Amsterdam (staying with the same employer) and my salary was cut by roughly 40% for this reason.
For a remote company, the approach to hiring might be a little different. They need a new engineer, they budget the new engineer, not knowing where the engineer will be located, so even if the engineer is located somewhere cheaper, lowering the salary won't be too much of a deal.
That's usually what you see. For example, buffer will pay 100% for SF and 85% (I think) for a city like Amsterdam. That different is much lower than what you'd get at Google, etc.
Well, Google tends not to favor remote. However, at least within a given country, a lot of companies who support having remote employees don't vary salaries a lot based on where you live. Of course, many things go into how much someone is paid and competition with local companies may be one of those things. But most companies with remote workers aren't going to suddenly give you a big raise if you move from Akron to San Francisco.