customized publish sorts – Understanding capabilities parameter in register_post_type()

Up to now what I’ve understood:

Capabilities parameter permits the plugin to set edit, learn and delete capabilities for a sure post_type relevant to the all person roles. The primitive capabilities are a by-product of those. For the eight different primitive caps reference by way of map_meta_cap, ought to the coder manually set every of those for every set of roles or are by default set in response to the meta caps?

Additionally why the necessity to specify the capability_type to be used in?:

[cap] => stdClass Object
(
    // Meta capabilities

    [edit_post]      => "edit_{$capability_type}"
    [read_post]      => "read_{$capability_type}"
    [delete_post]        => "delete_{$capability_type}"

    // Primitive capabilities used exterior of map_meta_cap():

    [edit_posts]         => "edit_{$capability_type}s"
    [edit_others_posts]  => "edit_others_{$capability_type}s"
    [publish_posts]      => "publish_{$capability_type}s"
    [read_private_posts]     => "read_private_{$capability_type}s"

    // Primitive capabilities used inside map_meta_cap():

    [read]                   => "learn",
    [delete_posts]           => "delete_{$capability_type}s"
    [delete_private_posts]   => "delete_private_{$capability_type}s"
    [delete_published_posts] => "delete_published_{$capability_type}s"
    [delete_others_posts]    => "delete_others_{$capability_type}s"
    [edit_private_posts]     => "edit_private_{$capability_type}s"
    [edit_published_posts]   => "edit_published_{$capability_type}s"
    [create_posts]           => "edit_{$capability_type}s"
)

Why not simply use the capability_type in index and set boolean values for every? like:

[edit_{$capability_type}] => bool