The thing is, people generally don't want to be responsible for organizing meetups. Many will happily attend but not host.
My guess is you need to find community leaders who can handle and own the responsibilities involved with hosting meets in their areas.
At the end of the day I don't think a website is going to help convince people to take on that kind of role. It's more of a personality thing.
With my club, we use Facebook events and generally just screenshot the details and further disperse them that way to discord, slack, instagram, etc. But none of that is enough alone for someone to host. Even when it's as simple as picking a meet location and time and sending out invites.