You having a successful career is not really relevant to the discussion.

I do agree though that the most important part of a professional life is to fill the gap within your team. But that's another discussion.

Its relevant in the context of showing just how little weight the 'devops is not a role' view has in the real world :)

if it were to be called "Release Engineering" and the pay was the same, would it matter?

Totally agree. In my experience it seems engineering titles and the associated role/duty are wildly inconsistent between companies. The company size and industry have a huge impact.

For some reason "DevOps Engineer" is much more polarizing than "FullStack Engineer" or "Senior Developer"

How do you double your income yearly?

Heh I may have exaggerated a bit to make a point ;) realistically its more like every 2 years or so, and partially because I started from a junior role in an enterprise environment and worked my way up to independent consulting.

start with very low income and only have a small number of years in industry.

15k -> 30k -> 60k -> 120k

For the first couple of years it's possible. I'm not sure it's going to work past year 3 or maybe 4.

Part time junior -> full time junior -> senior -> lead over 5 or 6 years.

Also if you have stock at a successful company in the past couple of years things have gone vertical.