[mezentius]

I’m guessing you haven’t worked in the film business, as ‘more efficient’ is not the same as ‘brighter’ in real-world conditions on a film set. LED lighting brings efficiencies in power use, weight, and heat, but nowhere near the quoted figure in terms of raw output due to optical loss, color control, diffusion, among other things.

Unless you are James Cameron shooting Avatar III on a soundstage with (close to) a blank-cheque from the studio, you are still limited in terms of space (the constraints of the location given the size of the light and its supporting stand), time (the time to set up and adjust each light properly, including last-minute adjustments), labor (someone’s got to plug all that in, run the cables, etc.), and cost/availability (you don’t always get the lights you want for a given budget).

Beyond that, you’re also considering aperture and ISO from a creative standpoint; maybe you don’t want to shoot wide open for reasons of image control, and so you may spend your lumen budget on ensuring that a particular scene can be exposed at, say, f/5.6 at ISO 100. Or you may want to spend your lumens on lens filtration, which produces a specific effect but further cuts down the incident light.

In short, no, you do not have 10x light available to spend on frame rate, and for any marginal gains in raw output, most cinematographers are thinking about what creative choices it opens up for the film; I would never burn additional lumens to shoot at 120fps just for the sake of A/V fanboys on the internet, unless the scene requires slow-motion or high-speed capture for postproduction reasons. Technical choices in this industry should always be motivated by the need to solve creative problems effectively, quickly, and within budget.