“If you can't feed a hundred people, then just feed one.” - Mother Teresa
It depends what you mean by 'make a difference'. The simple answer is 'yes'.
If you want to make a great, massive difference then of course it's going to be harder. The impact in the world you can cause is a direct correlation to the pwoer you have focussed. Someone with a lot of power, like Steve, could be a great influence, but someone with less power, like myself, much less so.
Any positive difference in the world though is worthwhile, depending on what it costs you. If you change the world for the better then the world is better. Full stop. That's the reality of it.
What it comes down to is -
How can you leverage your skills and abilities to increase the amount of impact you have?