Hmm..
We play D&D exclusively using our computers.
I'd argue that D&D already exists as a computer game.
Heck, as a mulitplayer, co-op experience it's the best we've played - the graphics and community are awesome!
As for 'video game', it's an interesting example of how folks have become conditioned to associate a certain level of aesthetic and technical sophistication with a medium. What's the difference between a computer game and a video game? Does it matter? Do we need X quantity of art assets, Y game play loops and Z levels of empowerment to make it a 'video game'? If it's PC exclusively, does that change things compared to a game that is console exclusive? Or are these all mediums and elements for gaming as a whole? hmm..
One of my personal bugbears is the belief that a 'role play game' must have levels, classes, hit points to be 'D&D'. It's an interesting topic that I've discussed with my students a fair few times. Sure, I have played Baldurs Gates I & II, Icewind Dale, POE, Neverwinter and all that jazz -- I enjoyed those games to varying degrees but they always felt like a poor piss poor imitation of what we do every week using our PCs, Discord, Photoshop/Illustrator/Google and our heads. Saying this, Divinity Original Sin 2 is shaping up nicely and will feature a DM/GM mode!
Anyway. If the criteria for 'video game' is, 'digital art assets and automated systems handled by a computer' then I'll throw a vote for Vermin Tide - it's pure hack and slash madness, a beautifully grimdark setting and a lovely co-op experience. That, to me, is an example of a game that makes great use of the current level of gaming technology to provide an experience best suited to the digital medium - and perhaps more importantly, one that is unique in the sense that we cannot create it easily without using a computer.