How do I disable controller sticks deadzone?

Hi! I've tried steps from the Arch Wiki, but the deadzone is still present and it's huge. This is really annoying and I wasn't able to find anything online that would fix this issue. Could anyone help me out here?
I'm using 8BitDo Ultimate controller via Bluetooth. Same issue occurs via USB connection and with DualShock 4 that I have.

UPDATE:

I decided to use 2.4GHz dongle to connect my controller and evdev-joystick was able to detect and affect settings for the 8BitDo controller now. However the issues is still preset, however I did get a few improvements. Even though evdev deadzone (flatness) was set to 0, it's still preset albeit smaller than before, when controller was connected via Bluetooth. Also force feedback (vibration) started working, something that doesn't work when the controller is in 'D-Input' mode (same as with DualShock 4, as it defaults to 'D-Input' with no other options). Issue is present in both Linux-native games and Wine games, X11 and Wayland also have no effect on the issue.