Illustrative example:

Mars Bank Inc. (my fictional bank), starts off with a basic offering: a debit card, a savings pot, and a really simple user experience.

People love it: "it's so much simpler than Old Bank LLC... who knew banking could be this easy!".

As popularity grows, they start asking customers what they want, and create a laundry list of features to add.

• "I want to send my savings pot to my family, to add money in"

• "I want a flexible overdraft"

• 
  

Mars Bank Inc. builds these two features, but now they need to educate their users about them—and actually organise them in their dashboard.

• What used to say "savings pot", now shows a status for who can view it (which requires a status key)

• There's now a new main nav item for 'Overdrafts', with onboarding steps

  This happens routinely, and repeats every month. After a year, those 24 'simple' features now represent 80% of all the functionality.

The simplicity that the customer loved, is now a complicated dashboard, a suite of tools, and features that they'll never use.