In The Matrix, there is a human resistance, living in the real world and able to tap into the computer simulation at will, which is attempting to overthrow the tyrannical rule of the machines. The Machines are a highly advanced population of sentient artificial intelligence and major antagonists in The Matrix series. The Matrix Trilogy is one of the most complex and layered stories in film history, rife with hidden symbolism and open to endless speculation, and the ending of the franchise is no different. Why did the machines do it?

Some of the world’s richest and most powerful people are convinced that we are living in a computer simulation. Led by Neo, who can manipulate the Matrix at will, they battle against sentient programs out to kill them, in attempt to free the human race from slavery. The machines figured out when the first perfect Matrix failed, because no one accepted it, that it is the nature of the human mind to inquire and choose. In the movie, Keanu Reeves's Neo, a … And now they’re trying to do something about it. Considering that the original question is,"Is the basic premise of of humans as a power source in The Matrix reasonable?" How could they justify a world whose inhabitants are systematically deceived about their fundamental reality, ignorant about the reason why they exist, and subject to all the cruelty and suffering that we witness in the world around us? The films of the Matrix trilogy pit man against machine in a clearly drawn battle, but they also reveal that the humans are more machinelike than they think, and that the machines possess human qualities as well. The machines have adapted the Matrix over several versions, but obviously the flaws needed to be built in in order to offer a choice bewteen sleep and waking.

The humans plugged into the Matrix don’t realize they are in a simulated dream and sleep through their entire lives.

From the article,”Do Machines represent a Threat to Humans,”Micheal Gonchar talks about how machines can affect humans and make things easier for humans. The answer is yes, every form matter in the universe contains energy which can be converted into power. The machine responsible for creating and managing the Matrix; The Architect, who had previously failed at creating a perfect world for the humans to live in not once, but twice now, had finally come up with the solution to his failures.

Not asking how or why the machines used humans as a power source. The humans, for their part, are as relentlessly driven as machines. (Human brains may be many things, but efficient batteries they are not.) The concept of turning human bodies into batteries seemed like total bullshit to me when I was a child seeing The Matrix for the first time.
I do not think that machines are a threat unless they are meant to be a threat to our community.

The freed humans (who have access to the real truth) relentlessly fight the Machines in 1) the illusory computer-projected Matrix, and 2) the deeper, ‘real’ netherworld. The Blurred Line Between Humans and Machines.

Humans are used as a source of electrical and heat energy by the machines.
With humans plugged into The Matrix, the AI could tap into bioelectricity that the human body produces.