How often do Digital Transformation initiatives fail to achieve the desired impact due to inadequate Change Management?

These initiatives focus on the technology, ignoring the impact on the people, company culture, mindset and old ways of working. The assumption is that a 'shiny new' - solution, application or process - will fit seamlessly or will be easily adopted. Funny enough, this is a well known pitfall but continues to reoccur.

Most employees that have been through a digital transformation implementation will hear phrases like:
"This new solution is easy to use and self explanatory".

"The new solution will immediate increase your efficiency" - this ignores the time required for a person to learn a new way of working.

"We have created an easy to understand online or web-based learning to bring users up to speed" - this assumes that we all learn in the same way or at the same pace. Some users respond better to face to face training sessions.

2 Questions:
- How does effective change management enable the speed of adoption on digital transformation initiatives?
- What does good change management look like to you?