Did you ever wonder why we have such a thing as “trial by jury”? Why not just let the judge decide? Throughout history there have been judges, and there have been evil judges, those who would rule unfairly for nefarious reasons (such as bribery). The natural solution to this problem is to “distribute the power” into the hands of twelve peers. It is far more difficult to bribe (or threaten) the whole jury, or even to successfully influence a majority.
The same wisdom applies to all those who exercise power over others. When the powerbase becomes too small, as it is now, we need to redistribute power to a larger base. That is basically what cantons are all about. Elsewhere on this website I noted that, to maintain the same relative number of legislators to population that was stipulated in the US Constitution, Article 1, Section 2 (1:30000), we would now need just over 10,000 members of the House of Representatives! The one thing that might accomplish is to make it more difficult for the majority to be influenced unduly by the army of lobbyists. It would, at the very least, make lobbying more costly. The problem with that still remains: the “representatives” still represent (at best) a majority of those who bothered to cast a ballot. And once elected, they can largely ignore those who elected them in favor of the special interests who more directly control them.
Cantons, which actually represent the people who freely choose to join them (unlike the so-called congressional “Representatives” who represent the special interests), can create just the redistribution of power that would free us from the dominance of the few to a very great extent.