None of those are offering 5nm right now. There are only 7nm foundries out there, the article says they are perfecting their 5nm processes for commercialization, what means there are some months (maybe years) yet until we see them.
Also, Moore's Law is dead by years now. Not only process improvement became subexponential and much slower paced, but transistor density isn't growing much and the core of the Law that is cost/transistor has increased with the last 2 or 3 iterations, instead of going down.
The jokes on me! What I mean to say is that Moore's law is transistors = 2^(t/2). That is it doubles every two years. But if that slows to 10% every two years, it's still exponential. Transistors = 1.1^(t/2). As long as the BASE is greater than one. I shouldn't have said exponent.
The very meaning of an exponential function is that any point t plus a fixed delta t the value is higher than the value at t by a constant factor. If that factor is getting lower over time it is not exponential anymore, even when it stays above 1. Otherwise you could argue that a quadratic function is exponential as well.
I have misunderstood your original comment. You are indeed correct.
Edit: I just noticed that the function which maps x to 0 satisfies this condition as well, but isn't the exponential function if we consider 0 as part of the domain definition. It doesn't matter much for our discussion though.
Perhaps you should consider the state of "maths" education wherever you're from, since you seem to be fundamentally confusing exponential and polynomial here.
Also, Moore's Law is dead by years now. Not only process improvement became subexponential and much slower paced, but transistor density isn't growing much and the core of the Law that is cost/transistor has increased with the last 2 or 3 iterations, instead of going down.