There are way too many plausible scenarios and even more potential outcomes.
But let's say for the sake of discussion no WW1 means that there's no War of that scale happening, not just our own timeline's one.
The truth is that all big powers have been gearing for war for over a decade. And war was a frequent occurence throughout the world in the 20 years prior to WW1. Heck, even in the region of origin of WW1 there was a big war that ended just a couple of years ago.
Austria-Hungary had stability issues.
The Ottomans had stability issues.
Russia was in a weird situation.
The whole of Europe had a socialist uprising vibe as well (Germany, France, Russia, Great Britain, Spain and Italy being important examples)
Even the USA had a growing socialist movement.
Nationalism in Europe was still on the rise and borders weren't really concluded in pretty much the entire continent with the exception of the Brtish Isles, Iberia and Scandinavia. And half of Asia and most of Africa was under colonial powers.
It is kind of obvious that war was going to break at any moment. Whether it would involve almost every party concerned would be the question. Also, civil war was possible in a number of countries as well. For example I think France would have had a civil war if how they reacted in WW2 happened during WW1 instead.
One of the scenarios that I have in mind is that the Russians would smell Ottoman blood and find a way to sneak their way into the Mediterranean which would have created a Great War. How?
Russia wanted access to warmer ports for ages, the Ottomans just kept losing to everyone that desired freedom and that also meant that Russia could have fought on almost every front. And winning such a war against an enemy of tha ages with the mask of a religious conflict on top of that, would have probably granted the Tsar more time in power.
The British wouldn't like this turn of events. But at the same time, Austria-Hungary would have been concerned about this since they controlled parts that the Serbs/Yugoslavs wanted. And desire from freedom wasn't really that low in those parts. Would it take a Russian effort to get those people to gain independence and place them under their sphere of influence for Austria-Hungary to react, or was the intention to bite a chunk off the Ottomans suffice? The Austrians could very well also smell the blood and go for Serbia to contain them under their political power as well, essentially doing what was done to Poland during WW2. But that would probably cause the British to get involved. But on whose side? Against both? So we have the British against Austria + Russia? Then Germany gets in the play and France sides with Britain? Seems like an odd turn of events from a historic perspective but maybe it was possible. But would any of these powers really care about the Ottomans? They all wanted a piece of that melting pie.
I don't see how WW1 could break between France, Britain, Germany, Russia and Austria. It had to be done via another route, just like in our timeline with the assassination in Sarajevo. Nobody really cared about Asia, Africa was a mess that was under control for the time being, so we're left with Europe. If it's not a Balkans involvement, it's a direct Ottoman one. Europe was in boiling point already so if anything happens to anyone during that time, it's going to be a big war coming.
The only alternative would be that everyone just sits idle while gearing up for war for ages with no signs of war breaking out. Which seems impossible to think about now, but could be some sort of Cold War thing that would also cause a technological leap.
Because for people claiming that we'd have better technology and all that, it wouldn't have been possible without the threat of war. War is triggers a kind of survival instict we humans have and that's what drives technological push. At least historically. Most of the technology we enjoy today are byproducts of stuff invented or implemented during war time. Computers, radio, telephones, means of transportation, satelites etc. With no threat of war, all we could do was polish existing technology. Just like we went from adding a camera to a telephone to then adding a second one on the other side. There's no technological thrill today despite the hype. We just have fancier products which get polished and improved over the years. Survival drives technology to new levels, not peace. As unfortunate as that sounds.