What is the pruposes of all these 'Full text search' app modules?

thanks that help. I read up and down the forum and GitHub but totally overlooked the simple explanation :face_with_symbols_over_mouth:.
Anyway to explain it in brief (again).
The core module Full text search basically makes others know each other. By others, I mean the other two categories to make search work properly.
There is:

  1. Providers Apps
    They extract content from your Nextcloud apps, currently only content fro:

    1. Bookmarks: Full text search - Bookmarks
    2. all files you can access via nextcloud: Full text search - Files
    3. the content of the above mentioned files: Full text search - Files - Tesseract
  2. Platform Apps
    They communicate with a search platform (ie. Elastic Search, Solr, …) in order to index the content provided by the Providers and make them searchable through the plattform search app, what will than be integrated in nextcloud.
    Currently there is only one platform:

    1. Full text search - Elasticsearch Pl

I hope the will be soon provider apps for note taking apps listed in Apps / Categoriess / Office and Draw.io and nextnote.

Could there also be platform apps for 3rd content, such as pocket?

WHY?
I saying and asking this, as I have quite a lot of mini project ongoing but I have to get them structured/organised now eventually.
Currently I’m bit inspired by OneNote’s ideas for note , see below, what could also include photo of business card of craftsmans, their contact and extract from email conversations.
So I think, in the end, when FullTextSearch can index anything (hopefully) in nextcloud and also may some important 3rd party content, it holds also the references to them. So it should be possible do this, what I mentioned before, by the means of nextcould’s apps.

So my vision is that I could use the search function to get also the reference to a content, e.g. mail, photo (by tags) or contact and include them either in a Deck card or note, as real object not just as string of characters.
The search shall be called pressing key-combination/shortcut, so it opens a overlying search window, what will integrate the selected result as object what shows its information inline, what basically should be possible by means of External sites.
You think that is realistic vision?