OC [original character] basically agrees with trad that the goal of the game is to tell a story, but it deprioritises the authority of the DM as the creator of that story and elevates the players' roles as contributors and creators. The DM becomes a curator and facilitator who primarily works with material derived from other sources - publishers and players, in practice. OC culture has a different sense of what a "story" is, one that focuses on player aspirations and interests and their realisation as the best way to produce "fun" for the players.
This focus on realising player aspirations is what allows both the Wizard 20 casting Meteor Swarm to annihilate a foe and the people who are using D&D 5e to play out running their own restaurant to be part of a shared culture of play. This culture is sometimes pejoratively called the
"Tyranny of Fun" (a term coined in the OSR) because of its focus on relatively rapid gratification compared to other styles.
...
These norms were reinforced and spread by
"character optimization" forums that relied solely on text and rhetorically deprecated "DM fiat", and by official character builders in D&D and other games. Modules, which importantly limit the DM's discretion to provide a consistent set of conditions for players, are another important textual support for this style. OC styles are also particularly popular with online streaming games like
Critical Role since when done well they produce games that are fairly easy to watch as television shows. The characters in the stream become aspirational figures that a fanbase develops
parasocial relationships with and cheers on as they realise their "arcs".