They're also countereffective, since dictatorship uses it to push story that "they are against out people, we all suffer but if we stand together (under our rule) we'll prevail". And from what I saw at that time, people redirected their hate from government to evil foreign enemies. This seems to be the pattern in other countries where sanctions are pushed. They really make life worse for ordinary people, not those in power, who even use it for their own benefit.
On one hand, 90% of people can only hear official media. With sanctions, they have much easier job telling that someone else is to blame.
On the other hand it makes much much harder for political opposition to fight that narrative, to propose opening the country towards West when they're clearly acting against population through these sanctions.
That's why these sanctions benefit regime, and that's why they're double evil - hurt people + make it harder for opposition to fight the dictator.
In Serbia's case, sanctions didn't help at all with overthrowing Milosevic. They just brought misery to ordinary people and he remained in charge through the 90-ties.
It took loosing all the wars, getting country bombarded by NATO and de facto loosing control over Kosovo, getting entire opposition united, and massive protests to remove him from the power.
[1] https://www.aspistrategist.org.au/bosnias-next-crisis/
[2] https://www.rferl.org/a/serbia-kosovo-dialogue-dead-selakovi...
[3] https://data.worldbank.org/indicator/NY.GDP.MKTP.KD.ZG?locat...
[4] https://europeanwesternbalkans.com/2019/12/26/depleted-urani...
[5] https://www.nationmaster.com/country-info/groups/Former-Yugo...
The paper also notes that "the success rate of sanctions has gone up until 1995 and fallen since then."
http://www.pages.drexel.edu/~cas86/GSDB_FKSYY.pdf
20-35% success rate of sanctions has been replicated a bunch of times. Sanctions are the foreign policy experts form of collective punishment. It seems they largely exist to satisfy the bureaucrat's need to "do something."
If a random individual attempts to "pressure" an autocratic government, they will land in prison or fall out of their window.