Which is usually not helpful for the country.
Yes. Unhelpful to say the least. Of course it depends on the system, the relationship between Head of State and Head of Government which does of course differ from country to country, however the result is usually stasis.
If the king has actual power, then it is not very democratic is it
Democracy takes many forms; there is no single model. Those countries, almost all among the most democratic, developed and stable countries in the world, who have a traditional Head of State, operate by consensus. The monarch's role is to advise, warn and admonish,. Also to make decisions, like a casting vote, if there is no consensus between politicians (usually if an election result is close or a Head of Government dies or is taken ill in office). They do this with the consent of the people, just as they have to abdicate when they lose that consent.
It works by trust and decency; in the vanishingly rare situation that is breached, there are of course mechanisms in place to mitigate it.
As you know, having a hereditary monarchy that has survived for over a thousand years is a sign that a system is working and has not collapsed through instability, dictatorship or revolution.