How to best avoid unwanted visitors to our meetings

I belong to a group that meets every single week.  Participants join the meeting by entering a meeting ID and an associated password.   The current Host represents a single point of failure, but has been reluctant to share the Host Role because of stated concerns about "hackers and trolls."  (I don't get the connection, but... )  My thought is that we simply set up the regularly, recurring weekly meetings using the Meeting Room feature so whoever is the Host has to admit any participant before the participant can enter the meeting.  Is this correct?  Are there other options?  Am I missing something?