My dream setup is two NAS servers, one at my desk, another at my parents house 2000 miles away sitting at the bottom shelf of my mom’s desk.

At this point I’d say there isn’t much incentive to make HDDs more data dense. For the cost of making an HDD with 50TB it would be easier to just buy two 25TB drives. Most people aren’t going to fill 20TB on a system. For content creators like videographers, architects, photographers, that store a lot of data and projects long term, a multi bay NAS setup is the go to