This period just seemed really slow compared to timeframes before and after. Most timelines on technology advancement I look at just skip through most of these years as there wasn’t much to tell. I know they’re called the dark ages but just curious what caused this decline or lack of notable innovation for over 1000 years and where would society be now if things were different
You have been reading some terrible timelines then. For some answers addressing your concern, try
It's easy to grasp the technological differences between now and a thousand years ago, but how different was technology in the years 500 and 1500 in Western Europe? with answers by /u/BlueStraggler and /u/Hergrim.
The number of technological advancements made between 500 and 1500 AD is sufficiently large that even a basic summary of them would fill a small book (Cathedral, Forge and Waterwheel, by Frances and Joseph Gies).
For some more specific examples, try the thread here.