How do you describe Discovery's 'Endgame Content' or 'Maxing Out'

[Antonio]

To put it bluntly - there is no absolute maxout.

A relative maxout would be when you feel you have enough characters you want to roleplay with, reached the level of roleplay you intended to acomplish when you made a character and/or own a certain amount of cash to equip the ships of those characters.

The key word here is relative - said maxout can change at any given moment, should the player feel the need to create more characters, equip more ships or continue progressing through roleplay. If one reaches a point where he maxed out completely, chances are he will get bored quickly because there are no goals he needs to fulfil anymore and he continues playing the game "just for the sake of playing". That's why none of us actually can max out, otherwise we'd just stop playing the game altogether or set ourselves a new goal (be it making ships, progressing roleplay or something else) in which case we aren't maxed out anymore.

Relative max outs are a common thing, and they eventually go away simply for the sake of a player to keep developing himself and his characters on one way or another.