Just to be clear, I'm not advocating ageism at all. I'm in my 40s, write about ageism somewhat frequently (1), and tend to work with candidates that are closer to my age or older. On Monday, I should be getting an offer letter for a female engineer who started her career in 1988.
I don't necessarily feel that appearances matter more than reality, depending on what appearance you are referring to. We're talking about resumes here (or at least I am), and we're in an industry where some (often the young) have opinions about the older members of the industry. This isn't new, and it's not even specific to the industry.
The reason I'd suggest trimming the resume is so you can actually be invited in to have that conversation where you can then convince someone who might be ageist that their bias is incorrect. By including information that makes it obvious you are of a certain age (for some it could be 30+, 40+, 50+, 60+), you are giving someone the ability to discriminate.
It goes the other way as well. Workers in their early 20's might want to appear (on paper) as old as reasonably possible.
The reality is that lots of older workers know their stuff, and will only be able to change the minds of those who discriminate by getting in front of them. I'm not suggesting "by any means necessary", but I have on issue with the tactics I suggest.
I was referring to resumes/CVs as embodiments of appearances, although now it occurs to me that web browsers are essentially appearances portals.
I guess I'm just disappointed that the "Information Age" became mostly about titillating a mostly passive audience into drooling over screens. Whereas I had a seemingly eternal career working on what used to be called "middleware", it now seems to be impossible to get noticed without droning on about one's vast "full stack" experience, which on closer examination seems to be mostly about ADHD-like rushes from one Javascript and/or MVC framework to another - again, mostly in the service of wowing the senses of screen addicts.
I'm also kind of stunned by the seemingly universal belief that there's really that much difference between underlying tools that make machines sing, and that anyone who was ever profoundly well-versed in one set of tools couldn't quickly come up to speed on yet another syntax. That, in other words, the word 'generalist' has become a curse, while the parroting of anything ending in '.js' a red-carpet-unraveling blessing.
I suppose the increasing speed at which new screen junkie drugs must be deployed to become relevant/profitable has something to do with it.