Gray is one of my favorite colors. I’ve decorated my office using various shades of gray and grey-centric hues. It looks good because I made sure there’s plenty of contrast, especially under natural light.
I agree, what they did to this house does not look good and it feels like a hotel. I’ve been in hospital rooms that were warmer and more inviting than this.
I’d guess these photos were taken for a home listing and that the bright and neutral paint color was intentional. Repainting walls in white or light neutral tones is common advice from realtors because it makes rooms feel brighter and is easy to paint over.