I am sure you will get very different answers from different posters on these questions, industry and location are big factors. Even more so from people who “know someone” who started up six months ago and now has the lifestyle of a millionaire, but very few know someone who failed and has lost their house and life savings.
Speaking personally and about automotive in the UK I do not earn near what I was two years ago before I started my own company. Having said that I don’t think many companies do, speaking as a rule of thumb if you quote what you got four or five years ago for a job you will be 30-40% to high, that is the market place. There have been huge redundancies and closures in the industry. Other factors come into the equation, for example it is almost impossible to be competitive in the USA with the current pound-dollar exchange rate.
Having said that I have a wonderful office in a rural location, no long drive in congested traffic and I still do what I know and love and I am my own boss, well at least to a degree, customers are far more demanding than any boss I worked for.
So to answer your question am I better off? No I work longer hours for less money and with no perks. Am I happier than I was two years ago? Certainly.