Online multiplayer is the present and future.
It's really not. Both online and offline experiences will always have their place.
Stuff like Uncharted/The Last of Us will always be popular because it's a great experience.
GTA V was selling tens of millions of copies before online was even active, simply on the single player alone.
The Witcher 3.
XCOM.
Stardew Valley.
Bioshock and friends.
And so on and so on.
There are heaps and heaps of really successful games wholly or largely dedicated to the single player experience. Some tend towards a storytelling angle, others are more about puzzle solving or strategic decision making. But single player will always have a place because it gives the developer more control about what they present to the player and how.
Even in racing games, which seem like a genre that would lean towards multiplayer due to the competitive nature, I think there's a lot of room for good single player games. The zero-to-hero game style appeals to a lot of people, as does the Pokemon style collect-'em-up. Both can arguably be done better as a single player game.
Then there's the people who just want to tune, or hot lap, or beat specific challenges. One of the great things about a single player race is that it provides a reasonably consistent challenge to all. Beating Mission 34 in GT4 felt great because it was a non-trivial achievement.
There's more than enough room for single player experiences, even in the racing genre.