World War I set in motion events that defined the 20th century. At the risk of over simplfying history, World War I caused World War II which then created the Cold War, which then left an ancillary racial war that disintegrated Yugoslavia. Interestingly the place that began World War I.
Yeah I know there's more to it than that.
But is the world better? I guess it depends on what standard "better" is being judged? Technologically, medically and food-wise, yeah there's no doubt we're better off than the average person was in 1914. I won't argue with any positivity mentioned on this thread. Hell flush toilets and air-conditioning alone make the world a better place for this pampered little American.
On the flip side, we now have the ability to destroy all life on the planet. We may have started a process, arguably just beginning in 1914, that changes weather on this planet. If so, we do not know what impact this will have on humans, but current projections are not favorable. There is still slavery. Much of Africa and Asia face a struggle daily to find food and water. Half, or more, the planet's population lives a life of bare subsistance. This is no different than the life they faced in 1914.
In the western world, we have based our society on not just oil, but cheap oil. Those days are nearly at an end. There is no alternative in sight.
Overall I think things are better now, but I also think it depends on who you are and where you live.
Chris