There was no real use of air forces. The artillery was largely ineffectual against entrenched troops. Chemical was a VERY double edged sword.

So you were really only left with a creeping barrage or a mass formation running to the other line.

That was the biggest lesson learned in WW1 don't become entrenched because it becomes a war of attrition. Hence the German changes in WW2

From what I understand, WWI was a big transition point for military theory. The kind of modern combined arms warfare you see in WW2 and beyond (the close coordination between artillery, armor, air assets, etc. Think of German blitzkrieg) wasn’t really developed yet. In the late 19th to early 20th century you see the emergence of new technologies like smokeless powder, breech loading rifles, machine guns, better artillery, and more, but many of the commanders of WWI had their military education of the previous age of warfare, where massed infantry and use of horse cavalry carried the day. So while more modern weapons were being developed, the knowledge of how to use them wasn’t caught up. Also perhaps the commanders didn’t comprehend just how devastating machine guns and artillery could be

The French military at the time had a belief called elan vital which meant that the individual fighting spirt of the soldier was more important than the weapon itself. So lots of early battles the French had massive casualties in such frontal charges for little gain because of this belief in fighting spirit. The British had like 60k casualties in a single day at the Battle of the Somme.

There were innovative officers (ex: US general Patton of WWII fame fought in WWI), but there were also really stubborn commanders (the Italian Luigi Cadorna, who fought no less than 12 battles at the Isonzo River)

So yes there was a lot of “going over the top” as you see in movies, but there was a lot of innovation happening as well. Read about the German Sturmtruppen or the Italian Arditi, who were renowned fighters with unique tactics. So an oversimplification is that WWI saw a lot of archaic tactics and beliefs used, but it also helped give birth to modern warfare.

The military history WWI is fascinating. I hope others can add their knowledge to this comment as well, mine is kind of a scattershot of ideas. Indy Neidell has a fantastic channel called The Great War where they covered WWI week by week in real time over four years.

If one side wanted to attack the other, the better option would have been to go around the flank of the other's entrenched position. But the trenchworks had been extended from the sea coast to Switzerland. So....

On top of what others have said I'm gonna throw in that we made new technology faster then we made new strategy's and we once starting fighting and tanks and gas and other weapons were used and it became a stalemate and going over the top and throwing bodies at the enemy is a tried and true method. We do see near the end of the war new strategy's used by German stormtroopers who used in infiltration tactics on weak parts of the allied line which would then pave the way for regular infantry to exploit the disruption in the allied lines.

As a political science professor of mine once said years ago, World War I is best understood as a point of human development where our ability to invent new ways of killing people outpaced our ability to truly understand and control it.

Prior to WWI, battles were still fought with horses, and those who were senior officers and other military type people had grown up in an ecosystem and culture where a professional knowledge of what did or didn't work was developed on battlefields and contexts that were very, very different from trench warfare. To give up on "going over the top" seems sensible, because we can theorize you'd be shot to pieces, but it would require committing to the idea that warfare was now a totally new ballgame and all of the old strategies that had proven efficacious in past battles (i.e., overwhelming your opponent with sheer numbers) was suddenly no longer viable. Old habits die hard.

I also think on some level that people became their own victims of propaganda and wishful thinking. If you think of your enemy only as idiotic, opportunistic cowards, it becomes more plausible to think they'll turn tail and run when faced with a remarkable show of bravery and force. Given that a lot of the iconography of WWI recruitment centered around every country being the heroes of their own story, and celebrating the valor and courage of young men, it's certainly possible that both at the level of the individual infantrymen and for commanding officers chasing glory and recognition of their own to think that this time a charge will work!. Especially when it always existed as a "Plan B" to the unsavory Plan A of sitting in a disease-filled, wet trench and waiting around for something to change.