Im currently making a costum 10x10 led matrix, and for it to be able to display senseable stuff, im trying to segment the display into 10 vertical lines which cycle at at least 100hz. Would a Python script on a raspberry pi be able to cycle its GPIO pins at this speed? Or Would an arduino or other Microcontroller be able to do it better?
This sounds kind of marginal to me, since you want the timing to be steady to stop the display from looking weird. You are better off with something like a Pi Pico and you will want to write the code in C (or similar) instead of Python. At that point 100 hz even on the main cpu is not a big deal. The Pico also has special i/o processors (PIOs) that can do this kind of thing more precisely even at MHz speeds, but they are limited and a pain to program.
There is an Adafruit board to control LED Matrices from a Pi with hardware assistance if you want: https://www.adafruit.com/product/2345
It says the current version works only on the pi 4, not the 5, for whatever reason. They are working on a pi 5 version.