What's the distribution of software engineers by decade across a 40-year range? Is anyone here willing to argue that it's completely flat? Of course not, there are far more SWEs in their 20's than in their 60's.
I have never once had my age be an issue at work or in an interview. My resume clearly states my work experience, and goes back 20 years. I don't have to hide anything, and I don't expect I ever will. Am I willing to believe there are employers out there who try to discriminate by age? Of course there are, just like there are fraudulent companies you could work for, sexist assholes you could work for, etc.
None of these matter because you don't have to work for these people. As a competent engineer your skills are in demand, and you get to pick where you'd like to work. If you aren't a competent engineer, no amount of plastic surgery will get you hired, and please stop using your age as an excuse.