Actually there can be problems with that approach for reasons of tolerance stacking in the gun, the brass, the primers, and even lot-to-lot burn rate differences in the powder, and most of all, with the person you are getting the information from, who may not have worked up the load safely.
And don't forget to allow for people's memories playing tricks on them, transposing numbers, forgetting to add the word "magnum", or making other basic errors in communicating the load data to you. I was at the range one day when a fellow handed me a fired .308 case that had the shoulder and neck blown out and asked me if that was normal. He was sighting in a borrowed hunting rifle whose owner had told him it was a .308. So he bought .308 ammo for it. The barrel was stamped ".30-06".
Only God is perfect. People make dumb mistakes. So take any load data you've been given or read in a forum like this and then go to Hodgdon or some other on-line load data and make sure it is inside a normal range. If there is one rule to reloading that is universally applicable, it is never to assume anything without checking. You likely know the old line about how you spell 'assume'.
The rule of thumb with trying loads is to work up test loads from a 10% reduction in steps no greater than 2% of the maximum or target load, while watching for pressure signs
. This is just a measly 6 shots incrementing up from the lowest load one step at a time, so it hardly represents a great expense in either time or components. It helps keep you safe. The caveat with time expense it that most folks hate making a trip to the range for just those 6 shots and don't want to assemble a bunch of ammo until they know the load is agreeable to their gun, so take those rounds with you (maybe a couple of each, in case you aren't good at seating primers yet) on the day you shoot up your remaining commercial ammo.
The only exceptions to all the above that I would make are with some low pressure target loads. Especially those that have been used by hundreds of thousands of people over several generations. A 148 grain lead wadcutter of any type over 2.7 grains of Bullseye in a .38 Special comes to mind as an example. Reduced loads with Trail Boss powder are another. In both instances pressures are well below maximum operating pressures for all modern cartridges and even for some not-so-modern cartridges.