I am of the opinion that a chronograph is a great tool and provides answers to questions that you might have had, but had no way to answer.
One thing chronographs have done is kill the great Wildcat era. After WW2, up to the time of cheap chronographs, the alpha and omega, the center of the universe, was velocity, and how to get more velocity. Used to read article after article about the latest, greatest, fastest wildcat, and how everyone had to have it. Once chronographs came out, shooters were able to compare cartridges and velocities. Very few of the wildcats were worth the fuss and feathers to own. The famous Weatherby double radius shoulder was a fraud, it did nothing towards increasing velocity. The wildcat era was built on bed rock ignorance. Shooters did not have the means to test the hype nor the apples to oranges comparisons that were in print. Once we had the means to test some of the claims, the era ended with barely a whimper. The whole construct was an advertising house of cards , a fantasy land created by Corporate advertising bureaus. A small puff of knowledge, and it all came down.
Palma shooters are very particularly about knowing the velocity of the their 155's. They have to get the speeds up to 3000 fps or more, or they don't get the performance they want. Every one of the good Long Range shooters I know, they know the velocity of their bullets. A number of them are very particularly in finding loads with low standard deviations and extreme spreads.
Barrels differ. My Krieger barrels produce higher velocities than my Wilson barrels. Since there is no such thing as a free lunch, those higher velocities were also developing higher pressures. Being able to see the high velocities, this confirmed my suspicions and I cut my loads to cut the pressures.
A number of times I have used Accurate Arms data in developing a load, only to find over the chronograph, that their published data was way different from what I was getting over the chronograph. Their 44 Special data was so slow as to be worthless. Something was wrong and using my chronograph, I was able to adjust the charges till I pushed my bullets at standard velocities.