How to achieve this look within unity3D? (2D sprites in 3D space)

Something similar to what Octopath Traveler did, or even something like Paper Mario. (i'm not trying to make games on that scale, i'm just curious about how the visual effect was implemented so that I can mess around with it)

I know that everything is a 3D space, i'm just trying to wrap my head around it. I haven't found any sort of examples or tutorials that go over this so i'm missing some simple concept. Just some explanation might lead me into the right mindset! Thanks for any help.

People have mentioned using orthographic cameras to fake the 2D look, or billboarded sprites, or just attaching a collision to a sprite, but still i'm having trouble wrapping my head around it. Could anyone lead me to any sort of example??
Would truly be an immense help.

 

@LemmieBee
Yeah that game has a fantastic look.

Okay. I could be wrong, but somehow, I don't think they used an orthographic camera. I think that when they were making, the enviroment textures and characters, they used artistic tricks, to give them that 2d orthographic look. And I think that they moved/positioned the camera, up in a way, to fake/make everything appear orthographic.