Different movements probably effect different people in different ways, but for me, the answer would be yes.
I do a lot of farmers walks. I alternate light weight / long walk with heavy weight / as far as possible. My traps are one of the places I feel I have developed the most, and my forearms are pretty good.
The thing about farmers walks is they helped me in many, many ways besides just mass building. I think these benefits provided synergies which then in turn, helped me add more muscle mass. My posture will improved, my grip improved (which carried over to all my lifts, especially pulling lifts), it helped my core strength, my mental toughness, etc. But at the end of the day, yes, they added mass.
TBH, I would put farmers walks towards the top (if not the top) of the list of what has had the biggest impact on my training in terms of specific lift types.