Hi, Lance_Montgomery !!
This might be good news for you as well, so I thought I’d share it with you. 
Of course, I don’t think Wix has officially announced support for this yet, so please proceed with caution before using it extensively. 
That said, I believe this could be a promising idea to fundamentally solve the issues you’ve been facing. Converting to AVIF is easy using https://squoosh.app/ 