Earlier quoted context omitted.
>The point of sanctions is to be detrimental to average citizens (aka voters) so that they can put pressure on Putin. This presumes fair and open elections
no, it presumes power exists by the grace of popular support, or at least a lack of motivated opposition. this often coincides with but is by no means restricted to elections.
For people to deprive the government of the popular support however, they have to vote with their life and everything. Look at Hong Kong. Look at Arab Spring. Look at Tiananmen Massacre. (They all ended up in vain, too.)
It's not some kind of natural process that will just happen.