It is a fact that the higher a framerate means a more enjoyable, more controllable, this is not up for debate.
Some of the best games (BotW) do run at 30 FPS, but they would be better enjoyed at 60, fact.
I know most of the people here are console gamers, who are limited by what hardware is made available to them so I have this question.
What are you willing to sacrifice for 60 FPS or higher?
One technique that could be employed is the splicing of 2D elements into a 3D world:
Super Mario Odyssey does this for far away NPCs in New Donk City.
For example instead of using polygon weapons in a first person shooter, you could use a 2D sprite.
It does not have to be a still image, you do some high quality animated renders of the polygonal weapons from a 30 FPS version of the game.
Another technique is letterboxing:
The PS4 Exclusive, The Order 1886 runs at 1920*800p (1.53MP, about the same pixel count as 900p in a 16:9 aspect ratio, which is 1.44MP).
Personally, I think this is a nice approach to reduce the load on a system's GPU, without reducing the image quality at the centre of the screen.
Fog / low draw distance:
Dropping the engine's load by restricting how far away objects are rendered.
Multi res shading and other, similar techniques:
Things like multi res shading, where you render the middle portion of the screen at full resolution and the outer portions at a lower quality.
Rendering at a lower resolution when the GPU load gets too high.
What are you willing to put up with if it means 60 FPS?