All these start-ups are in the US for a reason and it’s not just immigration.
It's in the US because VC firms are in the US, and VC firms are in the US because the US has an economy that produces billionaires, and that is mostly based on the USD being the reserve currency of the world, which is mostly based on the post-WWII world order.
The US was actually more innovative when it was more regulated. The biggest innovations in the US came from the public sector. Deregulation is not conductive to innovation.