There is this sci-fi book about this, but I forgot name/author. In the book a wormhole end can be positioned anywhere in space and time history. The tech starts as an ITER-like project and then becomes available in mainstream products, and all the dirty secrets of mankind come to light.
That is Arthur C Clark's last novel "The Light of Other Days", and it even has an Elon Musk like no ethics billionaire as one of the plot driving main characters.
Thank you! Yes, that is the one. I actually found it on my bookshelf just now, but in searching for "that book with the wormholes" several times before I never thought to check this one. Great sci-fi story.