We can see there is emerging complexity, we can see there is increasing ability to solve more and more complex tasks, we can see that machines can learn, we can see that they are able to work together in ever larger networks and across all devices, we can see that it's happening at an accelerating rate and we kind of know what exponential curves do, I don't see anything but evidence that this is a likely future scenario.
And unless you are saying it requires an intelligent designer to create intelligence which would make you religious I have a hard time understanding exactly what you are objecting to?
What we do know is that it's going to happen through technology and that's where we have the most ability to actually attempt to do something to steer this in the right direction.
Aren't the opponents of the belief in a technological singularity saying the precise opposite: that a designer can't possibly hope to mimic the effects of billions of years of biochemistry in reaching the little-understood goal of general intelligence in self-replicating organisms by designing computation machines and deciding on what outputs they'd like the evolutionary algorithm they've written to optimize for.
Technology exist I can see it, I can test it it's not metaphysical any more than the emerging complexity of biological life lead to us.
A very very different thing.