I think it depends on what ideas the programmer has and puts to work in the task of telling the computer what to do.

If the ideas are ideal, the program will be as small and fast as it can be, but if they are not then there will be an inefficiency.

That is to say, if someone shows you code that is smaller and faster, then it has more-ideal ideas.

Now few programs are built with ideal ideas[1] and people with "more capability" can use more simpler, less-ideal ideas to tell the computer what to do, but people with "low capability" must only use ideal ideas (or nearly-ideal).

But how likely it is someone with a low cognitive load capability could have the ideal ideas? If you think of programming as a purely incremental thing, then this must seem impossible, but if you believe in evolution then you can probably understand sometimes "weird things happen" and if the weirdness is successful, then you'll get more weird things.

It is for this reason I think the better programmer (more ideal ideas) probably has a lower cognitive load capability, but so does the worse programmer, so the important thing to focus on is a definition of "success", which on the long-scale will be different for the programmer than (say) the company they work for.

Put another way: If you want a job, then making sure you can program like others is important, but if you want to retire young, then making sure your program makes you money and runs forever is probably more important. What would your employer prefer?

[1]: If you aren't following what I mean by ideas here, Iverson calls them "tools of thought" and I can highly recommend reading: https://www.jsoftware.com/papers/tot.htm

I think you need to define "lower cognitive load capability" first.

There's a multitude of reasons why people can't handle cognitive load that all have different dynamics. The combination of traits I've seen lead to consistently less complex code is developers that are highly intelligent and hence more capable of building abstractions and who have a very low tolerance for frustration. The cognitive load of the spaghetti solutions they deal with grates on them a lot more than the average bear and since they are capable of seeing how to achieve the same task with less cognitive load they do it, so that they no longer have to deal with the frustration and can be comfortable.

I think you would probably find a lot of naive programming and other amateur mistakes. Maybe there's a sweet spot where you want to be just smart enough to solve the problem in an elegant way but too lazy to abstract and overcomplicate things.