I am wondering how much renderpower something like this needs:
thousands of bricks falling to the floor.
As a beginner in 3d physics I am not sure, is this something that needs a lot of power?
Or is it something that a smartphone could handle as well?
I am asking because I want to build such a brick tower for my smartphone.
Physics is considered an expensive operation. A phone will have a really really hard time doing what is shown in the video. I checked out the software used in the video Bullet (software) - Wikipedia
As you can see it is mostly used for pre-rendering. But it has been used in some games, but not to that extent of thousands of blocks colliding with eachother. The video also does not say if its pre-rendered or the hardware of the machine used. But its certainly not a phone or tablet.
If it was easy to do, we would all be doing it.
When using physics you really need to try out what works for your project.