IME if location is a factor, it's usually a different of 10-15%, so it's not like you're making $200k in SF and $80k in Ohio. More like 200k in SF and 180k in Ohio. YMMV of course.
I think it can range to a lot more than that. I make 400k as a senior eng in a big tech company in the Bay Area with 6 years of experience. I don’t think I’d make 340k-360k in low cost of living areas.
Yeah, you'd be looking at 80 - 100 here in TN. You might be able to get 150, but if you only have 6 years of experience you probably wouldn't be considered senior here either.
I'm speaking (from experience) about working remotely for big tech companies, not working for local companies. Based on the levels.fyi reference, I assumed that's what the parent post was referring to.