I know it is illogical, but I am considering giving up on the game because of my inability to create the party I wanted.
It's not illogical at all - me and my brother are long time D&D players and we assumed fully customisable teams would be a given, with the option to engage in parties with Origin characters if you wanted to opt for Larian's narrative journey.
But realistically - most D&D players are fine to craft their own journeys and want the options to play out multiple character builds in one go. My brother has 6 builds and I have 8 - I really don't want to have to run 8 playthroughs to experience all the builds I've developed over the years.
Fully customisable teams was the one thing I was looking forward to (It was even mentioned by the developers at some point) D: and I'm not even sure I'll be able to do the multiplayer work around as I'm on PS5.