If I want to separate files for each plugin, which is prefer to using require("plugname").setup() or lazy's retrun { } in each plug.lua?

[trans4jp]

case1:

.
└── lua/
    └── rc/
        ├── config/
        │   ├── plugin1.lua
        │   └── plugin2.lua
        └── plugins/
            └── lazy.lua
  

config_namespace is rc.config
lazy.lua load plugins config like spec = { import = config_namespace .. ".plugins" }
pluginX.lua (X is number) are written like return { -- Various plugins settings by lazy config }

case2:

.
└── lua/
    └── rc/
        ├── plugin-config/
        │   ├── plugin1.lua
        │   └── plugin2.lua
        └── config/
            └── lazy.lua

lazy.lua written like this:

return {
  -- All plugin with load setting 
  { "abc/plugin1.lua"
    event = "VimEnter", -- example event
    config = function() {
      require('rc.plugin-config.plugin1')
    }
  }, -- other plugin setting like above plugin1 ...
}

pluginX.lua (X is number) are written like require('pluginX'){ -- pluginX config }

Which is better?The only pro/cons I've noticed is that with case2, you can see all the plugins you put in a single file.

I also have another question, if something is installed by dependancy (e.g. extensions by telescope, cmp, etc.),Will the child plugin be lazy loaded according to the parent plugin's event? Or does each child plugin also need to write its own event?