Because we have elections every 3 years and PM changes when the public doesn't like it
If that's not proper democracy I don't know what is
From what you just said 5 prime ministers should of taken 15 years to replace each other if elections happen every 3 years. But in Australia you've had 5 prime ministers in 5 years and the public had no say init. It was conflict between both within the national and labour parties. The public had no say in it