"Sega broke ground in the late 90s with one of the first digital game distribution systems for consoles."

By the time this came on to the scene the idea was already 14 years old. Intellivision was doing it in 1980: https://en.wikipedia.org/wiki/PlayCable

The idea blows people's minds if they think of a TV channel as just a channel for delivering TV, but the concept is not that hard if you realize it's just a way to broadcast data, most of which happens to be television video signals. The problem is making it cost-effective for a console to have an amount of RAM normally associated with a cartridge. For most of console gaming's lifespan cart size completely outclassed RAM size so storing a full cartridge image in RAM was expensive for what was generally the low end of the market. Plus the RAM you could stick in the receiver put a firm upper limit on how large a cart you could broadcast, and in an era still undeniably ruled by Moore's Law the size of the more desirable carts tended to outrun the RAM put in these things so they tended to become rapidly unable to keep up with the cart sizes.