I don't know what to tell you. They obliterate readability for me.
I also genuinely believe these shorthands hinder access to research for the 99.9% of humanity who are not experts in the given field. Obviously, you do need to understand the context to use a formula correctly, but that also becomes harder when everything is written with hieroglyphs.
In university, I had to assess this paper. It took me 3 weeks to decipher that alien language, and it doesn't even say anything particularly riveting.

To address your points:

• I'm hoping that at least published math can be typed out with full names.
• I'm not opposed to local aliases. E.g. if the point is that some values in the matrix are negative and others not, then absolutely write "with air_resistance as 'a', the catapultation matrix is { a, -a, -a, ... }".
• I don't actually want to introduce spaces into variable names, that's just an example I randomly found online. I was rather thinking e.g. sine(euler^velocity_b).
  Bonus point: You can reasonably type it on a computer, because you don't need Greek letters and subscripts anymore.