Is easter island a warning from history we should heed?

There are a few lessons to learn.
One major one is economics and environmental sustainability. They destroyed the island because the trees were considered common property. A common property resource always gets destroyed when everyone takes according to their own needs. Sharing is not in our nature when economy is concerned.
Another major thing to learn is that cultures can become so focussed on beliefs that actuality escapes them. I don't call it false gods. I call it mass delusions. Like how Nazis took over Germany. The easter island culture was absorbed by a cult of personality with warped ideals and no care for the outcome.
Sadly we can never know for certain what lead them to loose sight of the destruction they caused. But we can learn that environmental disasters are swift and unforgiving. Don't focus on cultural values over the values of the earth.

That's what happens when you dye too many eggs.

Note to future-selves: giant heads are not an economical alternative to scarecrows.

Yes, send me all your money or the big heads are gonna get you!

makes sense......look what happens when you worship false gods !

Nowadays, they don't have to be statues.

We have...sport, workaholics, money,status, careers,

all false gods

Then there's buddhism, hindu,islam,shinto, wicca,...none have a ressurected leader, who can prove he/she is God

Yes. It has more to do with destruction of limited resources and environmental fragility than the giant statues, though.
Their island suffered a collapse--like many cultures throughout time (Anasazi, Mayan, Norse Greenland, even Somalia)--in this case, it was primarily an ecological collapse. Because the island is so isolated, they had nowhere to go once they had depleted their resources. It serves as an extreme example of the consequences of deforestation. They were trapped on a barren island, which led to starvation, a population crash, and cannibalism.

The parallels between Easter Island and the modern world are painfully obvious. If we keep treating the Earth the same way people treated Easter Island, eventually we will suffer a similar fate--on a much larger scale.