take into account inflation somewhere.
My expenses entered are the same year after year. shouldn't they increase by about 3% a year. Or is this somehow balanced with you not including expected wage increases in salary
Yes, this thing is flawed in that it does not take inflation into account. If you spend $30k/yr right now, this assumes you'll only ever withdraw that much. In fact, to support the same standard of living, you'll need to withdraw a bit more each year. With 2.5% assumed inflation, this means that $30k will need to turn into $60k over the course of 27-28 years.
Looking at it from the other side of the coin, if you only ever withdraw 4%/yr (or whatever you set it at) and don't reduce your net worth, the purchasing power of that 4% will be cut in half over the course of 27-28 years.
If you're a high-earning 30 yr old who has saved $1 million and think you can live off that for the rest of your life, you're kidding yourself.