Does Upload speed matter?

got a quick question , in our play group we have all crashed but not nearly in even distribution , and the only big variable is that our upload speeds are very different , the 1 friend has a lower spec PC , i have a mid level PC , and the other 2 have higher end PC’s and the only real difference is the upload speeds where seems like the higher the upload speed the less we seem to crash .

Upload speed defines how fast your PC can communicate back with the server. If it is too low you shouldn’t see crashes, but being kicked out of the game for the server not getting response fast enough OR stuttery gameplay.