It doesn't though. Raising costs by forcing a country to dodge sanctions is very effective. A supply will never entirely dry up, but it will shrink and become more expensive, and that's enough.
Though of course, sanctioning less developed countries like Cuba, Venezuela, DPRK, and Afganistan does successfully greatly harm their working-class population, and it has.
Sanctions on Russia have crippled their ability to get modern chips for their war machine, so they have to rely on Soviet tech. They hurt Putin personally so much that he went and bought an entire Presidential campaign.
Well that part is true enough at least. Capitalist Russia naturally can't innovate as much as Socialist/Soviet Russia could. Even its highly sophisticated public transport like in Moscow are stuff that the USSR built; they'd probably be filled with high-speed rail by now, like China is, if it wasn't overthrown.
It's just speeding up dedollarisation at this point. Trade is increasingly done in other currencies because the US dollar is just a minefield of sanctions and regulations. The US had this power back when they produced everything people needed, but nowadays everything's coming from China, so why involve a third party in your trade that can freeze your accounts for no reason?