This is just the software industry's fault. More engineers could be elite, maybe not in their first 10 years of their career, but what companies do is cut that short and push engineers away from the technical work, even after a few years. My guess is that the elite engineers had the opportunity to invest in their technical knowledge from childhood.
Perhaps the issue is that there just isn't that much technical work to go around.
While software was booming I remember hearing stories from EEs who found the opportunities in that field lacking. My understanding is that a lot of the people didn't do much technical or engineering work, but those who remained in the field became "BOM spreadsheet babysitters" and "Guy who's only here because we need a licensed engineer to sign off". It really pushed my away from that field even those there are many domains within it that greatly interest me. My understanding is that a lot of the hands on or technical engineering positions went to Asia along with the manufacturing
Instead of doing that, companies could structure to have less engineers with more technical work, and letting them specialize over many years. But part of the incentive is not wanting any one engineer to have too much knowledge in efforts to make them replaceable. It's an unfortunate side effect of how companies optimize things, and the consumer has no way to know or select this at the market level.
I think you're right that many more people are in theory capable of joining the group, but not that the industry is conspiring to keep it small. If anything it's the people who have an academic history that stretches back to childhood that end up dependent on having someone to guide and grade them. Beating your own path through the wild is scary, uncertain, and often thankless, so I think you'd only want to do it if you already felt sure you were among the most motivated and dedicated members of a group.
I think more of an issue here is that there is just way too many SWEs and we can’t all be “elite.” In my 30 years in I have worked with roughly same percentage of “elite” as the post is alluding to. The history/structure of just about every project I worked on boils down to needing two distinct group of SWEs, the inovators and closers. The inovators are the “elite” (within the project) and they figure all the shit out. The closers crank it out once all the shit is figured out for them