If caffeine does it for you and need lots of it, eating just caffeine is probably safer than drinking a lot of coffee. Coffee beans have a lot of of other stuff and it varies from bean to bean and eating a lot of some of that stuff may not be good for your gut/brain/whatever.

If you are "addicted" to coffee sometimes you will crave it if you do just caffeine, but this goes away after a while.

Be aware also that if you want the antioxidants and other stuff in coffee beans eating just caffeine won't give you that.