Let's take an example like a pipe as a weapon. In the PS1 days, you could take a rectangle and wrap it on itself and color it grey with a few pixels on it for "texture." Then you'd pin it to a character's low-poly "hand" and they'd swing it and knock into another character's huge hitbox and the other character would fly backward with a stock sound effect.
Take the same scenario for modern hardware. The pipe will start off as a 3D cylinder rendered at 4K and from there an artist will build it out with rust, divots, pitting, maybe some pipe fittings like a 90-degree turn with threading inside. It will have to exhibit some weight in the hands of the character wielding it, whose hands are no longer primitive triangles with some lines drawn on to represent fingers like on PS1, but are now fully scaffolded with individual joints for each finger. Those joints have to behave naturally, so they need to be set to have limits on their range of motion without them looking too stiff or it will break the immersion. Anyway, those fingers need to now wrap around that pipe accounting for the volume of the cylinder in the hand in a way that doesn't clip or stutter. From there, when the character swings the pipe, it needs to have "weight" to its swing, to the motion of the arm, the motion of the entire body needs to work in kind to convey realism, the facial expression of the swinger needs to change to reflect the action. Then it makes contact with another character and it needs to react realistically, and the other character also needs to react to getting hit realistically. Blood or sweat needs to spatter in a way that adds to the drama of the moment, a sound effect done by a professional actor needs to be cut in and timed correctly, as well as the sound of the pipe hitting the character.
I'm just riffing here, I don't really know what I'm talking about but the graphics alone on modern games can't just be spit out by typing "render realistic man hands" into the RPG Maker console.