I think I’d just change the mantle and the decor. I don’t find the stone that objectionable that’s go to the hassle of a makeover if there were other big projects to do.

This is if you can just change the mortar color to white. Or light gray.

I wouldn’t plaster over or whitewash the stone yet. The stone itself is already light and could work well with beige walls and light-to-medium wood floors. What makes the fireplace feel dated is mainly the dark mortar lines, the proportions of the mantel, the large star, and the amount of decor around the firebox.

I would definitely remove the star and clear away the baskets, vase, and other items currently placed in front of and around the fireplace. If the star leaves small holes in the stone or mortar, those could be repaired with a closely matched masonry repair material.

I would also replace the existing mantel with a thicker and longer wooden beam, possibly extending almost across the full width of the fireplace. If the required fire-safety clearance allows it, positioning the new mantel slightly lower would visually divide the tall stone surface and improve its proportions. Above it, I would use one appropriately sized piece of art instead of several smaller decorative objects.

The mortar could also be changed to a lighter warm gray or soft taupe to reduce the strong outlined effect around every stone. These changes would preserve the original fireplace while making it feel much cleaner and more current. This video shows the same living room transformed into four different designs through changes in color, lighting, materials, furniture, and decor. It may provide more ideas for updating the room without replacing the fireplace:

https://youtu.be/R-2ZyyBc6EY