Trading is easier with a large account because it provides you with enough margin to make a big move. With a large account, you will gain huge profit if you win and you will be able to maintain your account even when you lose. A large balance will also help you to execute long trades without worrying about margin call.
At a retail level, account size is irrelevant unlike the importance of trading with an edge. Account size problem arises because positions are sized wrongly relative to trade strategies by the uninformed on the risk of ruin. Size does provide flexibility on the pursuance of multi strategies.