There are probably good reasons for all of that, but it is just both bad DX and bad UX. It feels like you need to be a hardcore LaTeX expert or consult with one, in order to accomplish the most mundane things. Especially in a reliable way, that won’t break upon making seemingly unrelated changes, or won’t break other things itself.
I used Typst for a few weeks. It already feels much more understandable, consistent, hackable, and customizable. I guess that is the difference between an ad hoc macro system and an actually thought through programming language.
The only drawback I can see is the ecosystem being smaller and less mature. That is, however, counteracted by being able to do things on your own, without immersing yourself deeply in LaTeX for years. Also, it will improve with time.
LaTeX is great, don’t get me wrong. But its heritage and historical baggage is really dragging it down.