The BuddyBoss theme is the easiest way to build an online community on WordPress. The benefits of building your online community on a server you control are that you can modify, migrate, and backup your data as you see fit.
BuddyBoss is the only WordPress theme that I recommend that provides specific features. I usually recommend a theme like Astra or GeneratePress which is lean and fast, then you can use plugins to add additional functionality. BuddyBoss is the one exception to that rule, because it provides a complete social media like experience.
This year, BuddyBoss is providing lifetime access to their software for a one-time cost and for the first time, they are offering payment plans.