No it isn’t. The metaphor is that if you throw a frog into already boiling water it would attempt to jump out. If you start with tepid water and increase the temperature slowly enough they don’t. Sadly this was proven through experiment in the 1800s.
It’s an argument that if you make changes slowly enough people won’t notice.
Not really the point, but that experiment was debunked. https://en.wikipedia.org/wiki/Boiling_frog
In the experiment you mention, before they put the frog in the cool water, they removed its brain. Then they boiled the water. The frog did not jump out of the water because it had no brain. The experiment proved the opposite of what you are asserting.