Lack of single key Home/End and forward delete etc. All are somewhat possible with the Fn key, but that makes crazy combos and go to start/end of line also is a pain...
If you use emacs style bindings, then control+a goes to start of line, control+e goes to end of line. Forward delete is control+d.
If you use Wordstar bindings, then control+q,control+s is start of line, control+q,control+d is end of line. Forward delete is control+g.
The Wordstar, Emacs and Vi keyboard bindings evolved in the days before dedicated keys for cursor movement functions, so they are useful as long as you have the requisite additional modifier keys. I.e., like when you are on a laptop with a limited number (or none) of dedicated cursor movement function keys (or with those same keys hidden behind odd Fn keystroke combos that differ between any two different laptops).