Humans are susceptible to status quo bias. We are more comfortable with what we know, even if the outcome is not ideal, because we understand the results. When we implement change, given a chance, humans will revert to the old way of doing things.
To help our humans, we should always run trials & experiments to allow our teams to engage in the change, offer input and get comfortable with the results. Then, once the trial is over and we have decided to move forward, we eliminate the old way.
Frequently, companies run the 'old system' in parallel as a backup when moving to a new computer system. Often, the old system is never retired, and people continue to use it. Once the new system is stable, shut the old system down so people cannot revert.
If we change methods on a production line and introduce new tools for a process, once the process is stable, get rid of the old tools so people cannot revert.
When implementing change, change it enough that you can’t go back.