Usually, large organizations have already invested a large number of resources in existing monolith applications that represent the core of their business.

According to Gartner research (Kurt Potter, Sanil Solanki, and Ken McGee, Run, Grow, and Transform the Business IT Spending: Approaches to Categorization and Interpretation, Gartner G00308477, June 27, 2016):

Besides, there are also some examples, such as the one described in The Majestic Monolith (https://m.signalvnoise.com/the-majestic-monolith-29166d022228), that demonstrate that a monolith application is not the devil like someone has said.

So, why tear down the monolith?

The response is always the same. In most cases, the monolith has shown its limits in terms of reduction of time to market, having limited agility, making technology evolution difficult, being an obstacle to CD, and increasing technical debt, among other things.