Since 1945, Sweden has had a social-democrat leader for 55 years, 7 social-democrat prime-ministers. Guess what, none of them turned into dictators, as of 2017 Sweden was ranked #6 for GDP per capita and #9 for World Happiness Report
Since 1945, Norway has had a social democrat leader for 48 years, 7 social-democrat prime-ministers. Guess what, none of them turned into dictators, as of 2017 Norway was ranked #3 for GDP per capita and #1 for World Happiness Report