Yeah, I'm in team "fuck the launcher" as well.
And BG3 isn't even the only offender. It's becoming an obnoxiously widespread trend among publishers and at time even single developers.
Look, I already made my choice of what "launcher" I was the most comfortable with when I picked the store where I bought something. I do not want redundant bloatware and that's exactly what a "launcher inside the launcher" is.
Just run one of the executables in \Baldurs Gate 3\bin......
Still opens the launcher as soon as Steam is running. It's not that easy.
it's also worth noting that doing so just to avoid the Larian launcher basically forces you out of a multitude of Steam integrated features that someone may want to use (maybe even multiplayer support? But I didn't test it).