Page metadata can support nested info, and therefore would be fantastic to have structured data in pages, which would allow clients to easily edit content in a safe CMS based environment without having to go in the visual editor or code, which has caused clients to break layouts in the past, which normally leads us to recommend to clients to not touch pages unless they know what they're doing.
As a solution to this, we have often created Webapps with a single item in for the client to mange. Not only does this clutter up Webapps, but it takes the data out of context, and if not properly maintained, can cause fields to be redundant and not used as the site is updated.
It would also be a
mega
bonus to not have the fields named custom_field_2. It makes things so much harder.