Religion didn't hold humans back: humans held humans back. While religion was the vehicle used to suppress knowledge, science, literature, it was the men (yes, men) who ran the religions who did the suppression. It was and is about power and money, and the love of power and wealth (whether cows, gold, paper currency) is an inherent human trait. We evolved by fighting; we need to outgrow the issues that revolve around the need and desire for power and wealth.

Some atheists look at atheism as a panacea for the ills of humanity, but until humans stop being human, the ills will continue--and will do so even if religion becomes "extinct."

There would have been a lot less bloodshed

Much the same. People are the problem not religion, politics, neoliberalism or Marxism!

I think if there were no religion, something else would take it's place.

Well for one thing, 900 years of the 'Dark Ages' wouldn't have happened. to think of the progress that humans have made in the last 150+ years or so could have been exponentially advanced to the point that we could at this time have been roaming the Galaxy.

To farther that, let's take a time to ponder the so called 'Golden Age" of the Middle east.
For a few hundred years Places in the Middle east, most noteably Iraq. That was the trade center of the world. And not just cloth, herbs teas and such, but information. That time held some of the greatest Scientific advancements ever. And all of it came to a scheaching halt when religion in that area took over.
To this day they haven't broken free of that.

Yes, it was always about Power & Control.

Humans are tribal and will probably always find things to fight over.

Religion ... pure and faultless is this: to help widows and orphans in need and avoiding worldly corruption.

I guess if there was no religion, widows would suffer, orphans would have little no hope of survival and worldly corruption would be most likely worse than it is now.

I think religion was inevitable. All peoples had their myths, creation stories explaining the unexplainable in prescientific times. In was ingrained in us. Why am I here? Where did we come from? Where do we go? Etc. These stories are similar around the world. Before long outstanding individuals became leaders exploiting mans fundamental questions and religions developed.
If we weren’t so inclined we’d probably be more animal like or robot like. Maybe like a Vulcan. No evolutionary steps in between then and now..

I doubt if it would make any difference. There will always be people who are fearful and need something to rationalize their fear. There will always be people who want power over others, so will find a way to exploit the fear based people. There will always be fighting over resources. There will always be people who take charge, and some would be fair and benevolent and some would be dictators.

Like the Beatles song imagine

I describe it as one less thing to fight over. I don't think that automatically equates to more enlightened. Still lots of differences and tribalism to overcome.

We are what we are. Religion has been an integral part of humanity throughout its evolutionary history. There are some glaring examples where atheist leaders tried to eliminate religion, and they were all failures.

I think it would be more productive to develop more advanced religions than to wish for no religion.

It's nice to think we would have been able to navigate the human condition with fewer issues, but sadly I see no reason to believe that would actually be the case.

If there was no religion, then everyone by default would be agnostic or atheist. I have found that problem is not with the property of religion as such but within human need to find ways to dominate and control others. If not religion, maybe then region or skin colour, we would always find a way to discriminate.

We might be concentrating on science and not destroying the world today.

That very well had been the case if humanity have had started knowing what we know today.....well as we know, that's not how our history started. A smart and loving God would've started humanity wise. That's probably a good argument to prove there is no God.

If wishes were horses, beggars would ride.

There's a big distance between where we are today mentality and having made all good decisions through time.
I personally believe that bypassing all supernatural choices throughout history would have benefited us. But I have little confidence in our society to be able to make such a move -- at any level from organized religion to superstitions on down.

There was no religion in the world for millennia. Then we invented it. The world with religion is a very new phenomena so clearly the world can manage quite well without silly human inventions.

Wars simply would not be started BECAUSE of religion.

If that had been the case, we would probably have become Vulcan, instead of Human.

It would have never happened that way. Just look at our world today. Everything is about power and control. Religion is used in this game of power and control. It is nice to know that your god is on your side. You are the only one who has the right god.

If there were no religion, that would mean we're ALL agnostic.
Personally, I don't think about it all that much anyway, because I just have made peace ith the fact I have no idea, WILL never know, so what's the sense thinking/talking about it all the time?
As the Desiderata says, 'the universe is unfolding as it should,' so all you can do is make your way in life as best you can, be a good person, serve out your sentence, and die an honorable death.
It's fun to speculate about though, and since we've got to talk about SOMETHING, it's always a good topic of conversation.

People are the creatures known to have the greatest cognition capability, that is the thinking ability and ability to understand great or highly complex concepts. If you were to consider knowledge to think about and understand the Knowledge of good and evil is the greatest of knowledge, then you would notice "religious " text is what appears to have the copyright, so to say, on introducing the knowledge of good and evil to people kind.

Although believers will disagree I think the European "dark ages" when the Roman catholic church was all powerful held civilisation back for years.