You're missing the point that Vim still has the infrastructure of the original program -- it still has three separate modes: insert, delete and move the cursor, just as its distant predecessor did. This has no purpose except to agree with tradition.
Actually Vim has 6 basic modes, but none of them are "delete" or "move the cursor".
And the purpose of modal editing in the modern day is that, when editing and not just composing, you don't have to spend your day holding down various combinations of modifier keys.
You're missing the point that Vim still has the infrastructure of the original program -- it still has three separate modes: insert, delete and move the cursor, just as its distant predecessor did. This has no purpose except to agree with tradition.