I wouldn't implement it unless you're planning on using the types of scenes where it's shown to perform really well 

But clustered-deferred seems to perform better than clustered-forward for scenes with tens of thousands of lights.

 

The thing is - has there ever been a case where you will need 30 thousand lights in a scene?

There is a global-illumination technique where you use reflective shadow maps to generate thousands of virtual point lights from every regular light source, which could easily create 30K lights in a scene.

 

Plus,won't it get bottlenecked by generating shadow maps for all the lights

If you need to generate shadow-maps en masse, you could use imperfect shadow maps to render thousands of shadow-maps simultaneously.

I wouldn't implement it unless you're planning on using the types of scenes where it's shown to perform really well 

The thing is - has there ever been a case where you will need 30 thousand lights in a scene?

There is a global-illumination technique where you use reflective shadow maps to generate thousands of virtual point lights from every regular light source, which could easily create 30K lights in a scene.

Plus,won't it get bottlenecked by generating shadow maps for all the lights

If you need to generate shadow-maps en masse, you could use imperfect shadow maps to render thousands of shadow-maps simultaneously.