In case you didn't know, you can dash diagonally with Jett.

The reason you may haven't realized this yet (beside not playing Jett) is because something called N-Key Rollover (NKRO), which is a hardware limitation and it prevents you to press more than "n" keys simultaneously, in my case i can't press W+D+E at the same time, so i can't dash diagonally this way.

This can be fixed by buying a new keyboard without NKRO (or with a higher NKRO than your current one) or rebinding a new key for dash.

https://reddit.com/link/o2sicq/video/u92cf7drp1671/player