None of the previous concerns were true, largely because they came from laypeople who didn't understand the technology. A prominent exception is nuclear weapons, where their creators did worry their creations could end up destroying the world. I think most people would agree those concerns were justified, and it's not any lack of capability that means we're still here.
The motivations aren't unique here. Restrictions on the development of almost any technology benefits incumbents by providing a moat.
Employees inside frontier labs have the chance to make life changing money if they can make it to an IPO before the music stops. Have you considered that might be the reason they are so eager to claim "ai dangerous - regulate ai"? The nuclear scientists at los alamos did not have generational wealth incentivizing them to raise "concerns" to the public.
If your only evidence that the claim "ai dangerous - regulate ai" is true is "insiders who stand to make billions if they can regulate away the competition" told me so, that is pretty weak evidence indeed.
If a group of concerned scientists (without $$$ in stock options) demonstrated that anyone with one year of HS chemistry, an Amazon account, and a ChatGPT max plan could build a bioweapon 10x more lethal than an AR15 mass shooting or driving a truck into a crowd (because it is certainly more than 10x harder to make a bioweapon than either of these things, even with a theoretical AGI), then that would be worrisome. This is really not that high of an evidence bar but even it has not been met, but oh no we should start regulating yesterday.