Have come a long way
Definition 1 of 2
Pro Tip 1/3Positive Change
Use when someone or something has improved in a good way over time. 
The small startup has come a long way, now becoming a market leader.
Pro Tip 2/3Historical Progress
Suitable for discussing historical advancements in society or technology. 
Women's rights have come a long way in the past century.
Pro Tip 3/3Emotional Journey
Refers to the substantial emotional or personal growth of an individual or group. 
John has come a long way in overcoming his fears.