adding jquery at the very bottom I know how to add or attache a jquery/javascript file on the specific page.

My problem is that I'm trying to add jQuery file (included in theme) at the end of every thing in the body tag so any other file or module would not override it but can't figure out yet.

Is there any way to do that?

Example:
You need to set a dependancy on your library definition. e.g. if you want your custom.js after geofield then in the library you define custom.js you need to set a dependancy e.g.:

mylibrary:
version: VERSION
js:
  js/custom.js: {weight: 0}
dependencies:
  - geofield_gmap/geofield_gmap