2 Different 8x8 MAX7219 Animations assigned to different buttons - Big Delay

You are using for-loops with delay() both are blocking.

This means the for-loop must run completely through before other code can be executed.

You have to replace the for-loops by that natural loop that is always there:

void loop() itself.
The basic principle how you do this is explained here

If you are a beginner you will still have questions how to write this for your code.
Make a first attempt and in case it does not yet work ask again by always posting your complete sketch.

best regards Stefan