There were many medieval advances in technology, art, architecture and science.
https://en.wikipedia.org/wiki/Medieval_technology
There were serious scientific advances including the beginnings of the scientific method which goes back about 500 yeas earlier than the renaissance: https://en.wikipedia.org/wiki/European_science_in_the_Middle...
>There were many medieval advances in technology, art, architecture and science.
My favorite is the gothic arch because it basically decomposes into the math of man hours, calories and the work of moving stone. They didn't have the surpluses the Romans did so they were forced to invent a more efficient arch.
Medieval != Dark Ages
The Dark Ages refers to the 2-3 centuries immediately after the fall of the Western Roman Empire. The Medieval era / Middle Ages extend all the way to the start of the Renaissance.
Yes, I'm not denying that there were a lot of developments in that time period - more that there was a perception that things were declining, even if that wasn't actually true.