I wish there was an easy answer to this, but there isn't. I refer to your meeting attenders as badge collectors, strutting around the village proclaiming their importance. Whilst it is sometimes possible to engage an individual by finding a pet project in which they have a vested interest, there is no one-size-fits-all solution. If you can persuade them to attend training it might open their eyes to the potential, but converting that into energy and enthusiasm is not guaranteed.
The root of this problem is the apathy of the electorate. We don't have contested elections, so anybody who wants to be on the Council can be, without having to demonstrate their value to the community. We all dream of a world in which there are more candidates than vacancies, but that feels a long way off right now. I have some historic records of one of my Councils and the very first meeting in December 1894 when the first Parish Councils were established saw twice as many candidates as seats on the Council, so they each took their turn to proclaim publically why they were the man for the job. Obviously, women weren't included in the process at that time. It's chicken and egg. Many Councils are ineffective because they lack the right people for the role, but the right people for the role don't get involved because the Councils are ineffective.