Maybe for placeholders...but honestly it takes very little time to be able to whip up rough pixelart sprites and animations yourself. And they'll probably be better in many ways.

But a game's quality is honestly mostly art & music & other non-automatable creativity rather than the software. I highly recommend treating art and music education as core to indie gamedev education.

This is such a fun idea, actually. Sprites in general (not just 2D 8-bit style) could be really useful for DALL-E to generate. There are a good amount of tilesets and sprite packs for sale online created by pixel artists. But having sprites and tiles generated by DALL-E could really invigorate the indie game community.