Yeah, but HDDs are still kind of thick for a phone/tablet. I don't think it will happen.
In the past, Archos 80 G9 made a tablet with a 250GB mini hard drive, and some of the older iPod classics had a 160 GB mini hard drive. The iPod Classic 7th gen thickness is similar to most cell phones. The Archos tablet with a 250GB tablet was about as thick as cheap Android tablets.
The Archos tablet with 250 GB hard drive was never popular because most people rather get an iPad, or Cheap Android tablets made by Samsung and Amazon back in the past.
I also feel high storage space hard drive in mobiles maybe unlikely to happen unless the internet becomes worse, and SSDs and Flash Memory storage chips become very expensive because of a global shortage of SSD and Flash Memory chips.
A lot of people are satisfied with not owning their content like games, and are willing to pay $10 a month to use online services like Netflix, Apple Music, and Playstation Now to stream movies, music, and games from Netflix, Apple, and Sony's web server. People who want to play larger games like World of Warcraft, and Grand Theft Auto 5 on their phone or tablet will use a service like PlayStation Now Game Streaming to stream big mobile games to their phone or tablet over their Home Wi-Fi connection, or faster unlimited Data plan for their smartphone.