The method at the beginning is the standard way to subtract, and it is taught that way because it reinforces the concept of place value, in other words "that 2 tens is 20 ones" or "6 thousands is 60 hundreds", etc. The borrowing from columns then becomes a natural extension. It can also be taught using concrete objects to benefit kinaesthetic learners.
This "borrow later" method, while it may work, has the appearance of being created at random and gives no explanation why it works.
Also, I don't like how it says is the same as .
These are NOT the same thing, and will cause confusion to students when they begin working with indices. And since the purpose of this site was to avoid confusion, it seems like a circular argument to me.