If saving energy is so easy and profitable, why isn't everyone doing it?

如果节约能源是如此容易和有利可图，为什么不是每个人都这样做呢？

youdao

Plastic pipe is easy to install, and doing it yourself saves big bucks.

塑料管易于安装，你自己装的话会省下一大笔钱。

《柯林斯英汉双解大词典》

But what he's doing is so easy to follow.

但是他所做的是很容易被接受追随的。

youdao

It's very easy. Just fill in the blank with whatever action it is that you are doing.

这一点也不难，只要把空着的地方填上你正在做的事就行了。

I'm ~ing 课堂 - SpeakingMax英语口语达人

At issue here is the fact that by the time it is easy to see what the market is doing and that everyone agrees with your theme, most investors have already taken action based on the theme at hand.

FORBES: Biggest Investor Mistake: Absolute Certainty

You can get thousands of people to sign up for a donor registry, because doing so is pretty easy.

NEWYORKER: Small Change

Doing this successfully is not easy, and requires practice.

FORBES: Saying 'Hi' Through A Dream: How The Internet Could Make Sleeping More Social