The vaccine is not 100% effective, and its effectiveness wanes with time. This is from the Centers for Disease Control, which is a US government's highly respected organization:

Vaccine Breakthrough Infections: The Possibility of Getting COVID-19 after Getting Vaccinated

Nothing is perfect. You can wait around until a more nearly perfect vaccine comes along if you want, or until these vaccines that we have seem less experimental to you, but I'm in favor of going with whatever is available because this is a worldwide problem and it's very apt to kill many more people than it already has unless we do whatever we can to stop it.

The COVID-19 vaccines are not experimental drugs except that they haven't been around as long as other vaccines we're familiar with. In a way anything aimed at COVID-19 is going to be "experimental"--if you want to call it that--just because this is a new virus, and nobody on earth knew anything about it until it happened into our midst. Viruses are known to do that.