Esports take place over rounds or matches, which have defined lengths and objectives.
BG3 is a story based game where players can go long times without fighting at all.
What you are explaining would require a dedicated battle mode where players just engage in fights, stripped away from all of the accompanying story elements.
Larian has expressed no interest in adding this sort of gameplay to BG3, though they were producing a now scrapped DOS2 spin-off like this.
But even if they did make something like this for BG3, there is pretty much no chance it would gain popularity in the crowded esports arena. This isn’t what people look for.
And BG3 as some form of MMO is a pipe dream.
This isn’t the sort of game Larian is making. It’s not going to happen.
