If I'm entering text, I cannot move the cursor. Mode one.
If I'm moving the cursor, I cannot enter text. Mode two.
If I'm using a modern editor, these modes are not present -- if I want to move the cursor, I press the appropriate keyboard keys. Instead of pressing a letter key to insert a letter, I press the up-arrow key to move the editing cursor, without any preliminary mode-switching keys. This means an absolute minimum of keystrokes, and because there are no modes, the letter keys always insert letters, and the arrow keys always move the cursor.
All before beginning to discuss the mouse or other pointing devices, methods that have existed since 1963 and have been in wide use since 1980.
The reason I ask is because in vim, I can move the cursor with my arrow keys when I'm in insert mode, and if I wanted to, I can select blocks of text with my mouse, without pressing any key to change mode.
In addition to those features I can move about more efficiently without moving my hands from the keyboard, by changing mode. I touch-type, and I write for a living, so this is quite important to me, but assuming the features you mention are the most important ones to you and that you don't want to change modes, you can still do the things you say you can't. Well, I can. Not sure if you can, but I'm fairly sure it's not due to any limitation of vim. I'm curious how you appear to be mistaken in some very basic facts.
If I'm entering text, I cannot move the cursor. Mode one.
If I'm moving the cursor, I cannot enter text. Mode two.
If I'm using a modern editor, these modes are not present -- if I want to move the cursor, I press the appropriate keyboard keys. Instead of pressing a letter key to insert a letter, I press the up-arrow key to move the editing cursor, without any preliminary mode-switching keys. This means an absolute minimum of keystrokes, and because there are no modes, the letter keys always insert letters, and the arrow keys always move the cursor.
All before beginning to discuss the mouse or other pointing devices, methods that have existed since 1963 and have been in wide use since 1980.
Any questions?