Technically you are still paying for a license when buying a physical game. Not like you can play it anywhere else and without updates or installment of data its pretty much a disc in a box.
You can play it without updates. If Sony took down the PS4 servers tomorrow the game would still run regardless of whether or not you had the update files installed. Of course you can't play it anywhere else. It's a PS4 game. That's like expecting a CD to run in a cassette player.
Anyway if Sega starts releasing their games day and date on PC, and has prices like this at launch, I'll make Steam my go to place for Sega games.
If the PS4 servers go down, I wouldnt even bother playing a game on my PS4, would move on to whatever other platform has the game.
Thats like saying you would play OG FFXV unpatched to how OG FFXV is really like now after all the massive updates lol.