[bob1029]

This is an excellent point. It's fun to blame consultants, but the amount of M&A that has occurred can probably be implicated for half of the complexity seen in banking today.

The nuance with M&A between 2 banks is that one usually "wins" in terms of the core tech (i.e. where all the customers and accounts are ultimately stored) and absorbs the other. There are companies that specialize in this exact activity. The part where it gets super messy is with the jurisdiction-specific systems & procedures that have to be folded into 1 operational space.