Yes, you are correct about $70,000 being too much or too little, depending on where you live. And, salaries adjust to fit the area.
Many, many years ago I was in charge of hiring and firing all of the clerical personnel for a 100 person office. Our salaries in downtown Chicago were way below the same job's salary in NY, and way above what someone in one of our branches (Milwaukee; Minneapolis, etc. ) earned. Their cost of living was different than ours.
Still, no matter where you live, it is what people do with the money that finally determines how well they live and retire.
I had customers who never made over $40,000 a year who had everything that they wanted, and others who made $150,000.00 annually who were out of money all of the time.
Some people understand "Pay yourself first", by saving...and others who believe in "spend until you drop".
rich