Look at Blender and MediaWiki (the software running Wikipedia). They’re both FOSS and are developed and maintained by volunteers, backed by the end users. They’ve become such a big part of people’s lives, both professionally and privately, that they’ve become the mainstream choice.
I don’t know, but this feels like a step back. I haven’t downloaded/played a demo since, like, 2005. There’s usually a gameplay video or review on YouTube that suffices before I purchase something. Ymmv :/