Alex Denning at WP Zoom tells the story of the rise and fall of their page builder tool, including what they learned. The product existed for more than two years. After noticing the plugin, “created too much confusion,” and that it was overwhelming the small team, it was decided to discontinue it.
Alex’s says not all page builders are bad (a few are actually good), and they decided to start supporting the page builder from the theme — without bundling it in the theme itself — which I should note is what I'd recommend all theme authors do. As Alex notes:
Themes can utilise page builders without including page builders. Offer page builder support, but don’t necessitate users use it or bundle the plugin with the theme.