What is the best platform to start a community these days?

Over the years there have been so many platforms that have tried, failed, or somewhat succeeded. It still feels like this is an ever-evolving discussion. Is the best place to start just the place that most people spend time, like whatsapp? or slack? or should we look at some of the new standalone platforms starting, like Skool, or even Bluesky? It used to be that standalones were tough to maintain as it's yet another tool that people have to log into. Still the case or has AI softened people's attitude to trying new tools again if they're easy to use?