@jenallison Some people simply lack leverage in their bodies to use the pecs as main pushing muscle in horizontal motions so tension goes more than desired to front delts and triceps. Usually, when these kind of individuals end up being bodybuilders, one can see how much overdeveloped their shoulders are in comparison tontheir chests. Some of them is because of not bulging enough ribcages, some fail to retract scapula in an efficient way.... it's usually a combination of factors. For example, Spanish bodybuilder Roberto Castellano.
Chest pressing machines (AND cable presses) help with this issue due to specific adaptation to chest lines of force. With free weights, the body tries to find the easiest and most efficient way to move the bar/dumbbell from point A to point B, but with these tools you can accomodate your body to apply force in a path where chest is the main mover.
I would recommend first developing enough strength for reps in free weight movements. Up to 100-120kg bench/incline press should be enough, then if not engaging chest is still a problem, switch to machine and/or cable presses.
For me, cable presses are king. But they have issues. Too long to set up, occupying the two cables at the same time. Hard to initiate the movement if you're alone once you use significant weight and most pulleys are very limited in weight since they are usually adjustable double pulleys.