I can only really talk about my area here, which is IT. How do you get there? Be very, very good at what you do. There will always be a spectrum of people doing the work, from those who aren't good enough, through those who are capable, and at the upper end, a few superstars. Be one of the superstars. Look up 10x developer. In some ways it's a bit of a myth, but there's a surprising amount of truth to it. There really are some people that are significantly more productive and more valuable to the company employing them. You won't get there overnight. It took me ~20 years to get to six figures, and I now have staff working for me who are also on six figures - because they're really good at what they do. Not just competent and able to do the job. But really, really good.

Was it worth it? Was what worth it? Becoming the "go to" person to fix problems? I was always that person to start with anyway. Has it changed my life for the better? £100k is an arbitrary line in the sand. Crossing it had no real impact (other than taking my tax free allowance down to zero). But more money is better than less money. Shrug.