Single letter variables (including Greek ones) are great when they stand for something, or are well-known so they don't need to stand for anything.
If you stick to convention and use stuff like A for array, i for index, r for root, δ for small change (a delta), ε for error, Σ (Greek S) for sum, Π (Greek P) for product, etc.
It's only when you start using variable names as if they were free variables when they really aren't that you get into trouble with comprehension, especially from people not in your field.
I've been taking the approach of writing code at the highest level of trickery/abstraction that is well-supported by my automated refactoring, debugging, and static analysis tools. This usually means keeping code quite simple. I can then play around with the code much easier if I need to make any changes, and I don't have to focus on the details much because they are quite explicit.
If something is so detailed that it gets too long to be quickly readable I extract it into a separate properly-named function.
I'm definitely drawn to using all the tricks of a language and I feel like it would be a great way to show off how smart I am, but I'm not sure its worth it for sacrificing comprehension and ease of adding stuff in later. Maybe if everyone that will ever work or use that code is top-notch, that would be a dream.
The manufacturing process for semiconductors uses a standardized wafer size (in a given fab) so everything can be automated and simplified as far as possible. Having even something like just two wafer sizes makes a lot of the tooling/storage/transfer more complicated and expensive, so it's best to stick to one size and shape.
In order to have uniform rectangular slices of the silicon crystal, you'd have to slice off horizontal cylinder segments. And that would defeat the purpose because if you just used circular wafers you'd have been able to get a couple dies out of that area.
If you stick to convention and use stuff like A for array, i for index, r for root, δ for small change (a delta), ε for error, Σ (Greek S) for sum, Π (Greek P) for product, etc.
It's only when you start using variable names as if they were free variables when they really aren't that you get into trouble with comprehension, especially from people not in your field.