Two years ago I signed up to my first online community. Prior to that, I never participated in online discussions. That community was running Discourse. The only reason I joined was because it was the first time I saw functionality in a forum that compelled me to join as opposed to lurking.
I’m also a developer and found the community on Meta quite welcoming to new contributors. So I started contributing and have since built a handful of plugins for it. I have a strong bias toward Discourse as a result.
And since I’ve customized Discourse heavily via plugins for others, I know I can get pretty much any functionality I want with it. I know I’m not locked into anything specific as a result.
So my decision was effectively a non-decision. It never crossed my mind to consider anything else.