All the guys I seen over the years are strong on dumbells and weaker at barbell or the other waty around.
I am strong at barbell and stink at dubbell it comes down to which one you do more of. Most people get better at one than forgot about the other one. You can do both and get strong at both switch every other workout. If you want to go heavy on bench and can't find a good spotter at the gym use the smith machine thats what I use since my two shoulder tears.