Lmao holy shit, it's like a waterballoon full of jello around a spring. That's like early 2000s "we just invented jiggly bones but haven't nailed down the details yet" level animation.
I really don't mind if games want to do jiggle to be honest but this shit just looks bad, give it weight.
And I mean this for like, the entire body, facial animations too. If we shake our faces around or a strong gust of wind hits us our face MOVES, it's not a solid block of carved plastic, it's elastic. Skin hangs, gravity exists, our faces look different lying down vs standing up because gravity hangs parts of our face, this applies to boobs, fat all over the body, etc etc.
Give it real weight and gravity and it will look good and play a role in genuinely elevating the animation of the entire character. This shit sucks it's not progressed at all in over 15 years.
I think it's just that it's moving at all. Like if you wiggle a string or something in front of a cat, that's not a good mimic of real prey but the cat goes and freaks out trying to get it. Unnaturally jiggling breasts are a wiggly piece of string for oversexed weirdo men.
I don't think it's just a matter or early 3D physics being wonky. Plenty of Japanese anime and 2D games have intentionally exaggerated boob jiggles because of horny animators and a horny target audience that is obsessed with boobs, panties etc
I think to people like this goofy boob physics have very little to do with realistic simulation of soft body tissue and much more about being a signifier of whom the game is for
Upon cursory inspection it appears that this is not how bobs move in real life, but I will need a real life sample to compare against. Again, just for science.