Garrett Want describes this Star Trek: Voyager rivalry as "so high school"

Star Trek: Voyager was a tremendous show that had several different eras. The first was of course the pilot era; where the ship had to bring on Maquis crewmen to survive. The second was the Borg Era, which saw Kes leave the ship and bring on Seven of Nine as a permanent cast member. The third was the Seven of Nine era, where she became the face of the franchise much to the chagrin of Kate Mulgrew, who grew to have a rivalry with the Seven of Nine actress Jeri Ryan.

It's that last era that saw Ryan on magazine covers, promo spots, and being paired with the biggest guest stars, like Dwayne "The Rock" Johnson when he was at his zenith of popularity with the then-named World Wrestling Federation (or WWF). The show maximized Seven of Nine and Ryan quite well, but the issues between Mulgrew and Ryan grew, causing a rift that would last a while.

One cast member who wasn't having any of it, however, was Garrett Wang, who played Harry Kim and was once voted one of the most people according to People magazine.

In the book The Fifty-Year Mission: The Next 25 Years, written by Mark A. Altman and Edward Gross(via ScreenRant), Wang reveals what he thought of the battle for power, saying;

I don’t remember the comment, but Kate said something very snarky to Jeri and walked away. Jeri looked at me with a look of disbelief that said, “Can you believe that she said that?” I mouthed to her, “I know. I’m sorry.” She was so frustrated, she grabbed a phaser out of the holster of an extra standing near her and aimed it at Kate’s back as she walked away, pretending to fire. She was so mad. The whole situation was so high school.

It's pretty sad that Mulgrew, who now regrets her past behavior, was the one who was pushing the toxic behavior. Mulgrew and Ryan have since mended fences but it sure does seem like their rivalry may have been a bit more aggressive than we had realized.

Though, the issues they had with one another did parlay nicely into on-set chemistry, so at least it paid off in the end with some great television.