Go to Borderlands3\OakGame\Content\Paks and delete/rename the following files:

pakchunk3-WindowsNoEditor.pak
pakchunk3-WindowsNoEditor_0_P.pak
pakchunk3-WindowsNoEditor_1_P.pak
pakchunk3-WindowsNoEditor_2_P.pak
pakchunk3-WindowsNoEditor_3_P.pak
pakchunk3-WindowsNoEditor_4_P.pak
pakchunk3-WindowsNoEditor_5_P.pak
pakchunk3-WindowsNoEditor_6_P.pak
pakchunk3-WindowsNoEditor_7_P.pak
pakchunk3-WindowsNoEditor_8_P.pak
pakchunk3-WindowsNoEditor_9_P.pak
pakchunk3-WindowsNoEditor_10_P.pak
pakchunk3-WindowsNoEditor_11_P.pak

This skips all dialogue in the game, rendering it playable.