Why do the desires never seem to have an end?

Because ego is never satisfied. The desire is rooted in the wanting, not the having.
The trick is to want what you have. Contentment is the closet thing to sustainable “happiness” one can “attain.”

I think our brains are always looking forward to the next neat thing whatever that may be.

Desires are built upon the same principle which governs gravity which in turn mimics the grave, which is the way of death.
With their insatiable appetite it pull everything towards itself to keep it for itself, thinking by doing so they are established, Not realising that they are being diminished.

Desire is not to be negated per se, but transformed.
So one should develop the desire to share, and share by the nature of love, which negates the way of the death in that person.

Now that one is LIFE because of Love.

The thing that we don’t notice is that we go on doing things or going to fulfil desire because of earlier desires. You can build multistory only when you have the space to hide with rain or the cracking sun. Its the desire (not lust) that make humans a superior and most success among all other animals.

You should read about Buddhism.

I don’t think everyone is like that. Some people are happy with status quo. People who always have a new dream or desire tend to be one of two types. Very ambitious, or unhappy and never satisfied. We all have all these things in our personalities I think. Some ambition, some discontent, some status quo happiness.

I wasn’t a big dreamer at all when I was younger and I wish I had some more of that in me.

I think it was only sine the start of agriculture that humans knew physical satiety. But our behavior is tuned to always be hungry, because that motivation kept hunter-gather societies (what hominids were for almost always until recently) alive

While it can turn into something negative, I think it is a positive human attribute. You can be happy with what you have and still be future ambitions. I can think of few things I fear more than stagnation. That is to be in a cage.

Because it’s human nature, it’s inbred in everybody. People are never satisfied no matter what.

What you’re describing has been called the hedonic treadmill. It has its basis in our brain chemistry, specifically in the brain’s reward circuitry and the neurotransmitter dopamine. Dopamine is released by the nucleus accumbens, the part of the brain that steers us toward certain fundamental behaviors and gives us a little jolt of chemical pleasure to reward us for them. Dopamine=pleasure. When you have sex, that pleasurable rush is mostly dopamine. The great feeling of eating when you’re hungry or drinking when you’re thirsty? Dopamine. Getting that car you’ve always wanted? Dopamine.

Dopamine is quite literally addictive. That’s how your brain motivates you to keep doing those select behaviors. The rush of the dopamine dies away, you go into withdrawal and start looking for another fix. Going out to admire that car that gave you your last big rush won’t repeat the rush; this is the “habituation” aspect of the hedonic treadmill. It will take something else—something new—to give you your next big fix.

The dissatisfaction that keeps people frantically searching and chasing after stuff is just the feeling of being in dopamine withdrawal.

The first step in dealing with this is to understand what’s going on: that this is a chemical dependency, and that it just isn’t true that “if I could only get this or that, I’d be happy”, because that’s not the nature of the beast. You need to wean yourself from that addiction to dopamine, at least cutting it back to healthy levels. And you also have understand that pleasure—the dopamine buzz—isn’t the same thing as happiness.

People have never ending desires because they are all human and have a mind and can think. Desire is a part of our being and most of them are never satisfied with what they have. When one desire is satisfied then they move on to another one. This helps them to realize their dreams and goals and helps to keep life moving along.

Not to worry. Desires do end, but you do not desire how they do so. Just make sure that in the short time you have before they end whether you desire it or not, you don’t let your desires lead to too many undesirable consequences.

Desires are normal instinctual feelings, we needed them to survive when the species was not so blessed with plenty as we are today.
Several philosophical systems work to curb excessive desires as part of a path to peace of mind. Vedanta and Buddhism are examples of this.

@thorninmud said it well. At the root of human nature is an animal nature. Even in it most primitive form, animal nature seeks to survive and reproduce. Basic biological mechanisms produce the sensations of need and satisfaction that motivate actions to fulfill these desires. The same biochemical reactions responsible for guiding them exist in more complex brains and leads to complex desires.

Human societies have evolved opportunities for a plethora of pleasures promoted by those who profit by providing them. They stimulate such desires leading to a confusion of wants and needs. One way to limit how far one is drawn into a maelstrom of material acquisitions, and other self-serving pursuits, is to increase one’s consciousness of the needs of others and to develop a desire to reduce their suffering.

In the history of homo sapiens (humans) ,There has been lack of Food and Security. After millions of years of evolution,our mind constantly keeps seeking these two requirements and keeps storing more and more for the time of crisis. This is the mother of endless desire .