The rise of React made it clear that (reusable) components are an effective way of building a large web site (or web application) in a scalable way. Nanoc has support for partials, but they’re not a good alternative:
Partials are syntax-heavy (<%= render '/stuff', … %>, compared to React’s <Stuff />).
In Nanoc, Partials exist as layouts, which is confusing.
The implementation of partials depends on Nanoc internals, despite being implemented as a helper (while helpers usually only rely on Nanoc’s public API).