Change is not a one time thing. It’s a repetitive process because the first implementation will almost always not be 100% perfect. You need a few iterations with minor tweaks here and there and that’s where agile comes in. Short implementation cycles coupled with feedback loops allow organizations or teams or projects to find what works best for them. There is no one cookbook recipe type solution for agile transformation- This is where the mindset change & behavioral change (to constantly push forward and be better , leaner , faster etc) come into play. Most companies take many years before they are truly agile while the rest send a few people for scrum master & agile coach certifications that can be gotten over a weekend and then declare they’re agile. The second group is always the one that’s complaining that agile doesn’t work because they haven’t even tried being Agile. it’s a long game - no quick wins.