I am also NAL, but it almost certainly is legal to make backups for personal use. Breaking the encryption is the usual legal hangup, though there is no real enforcement on this front and nobody is stopping you from using Handbrake or MakeMKV.

More importantly however, is the fact that there isn't a meaningful argument that making backups of physical media you own is ethically wrong.

Oh I don’t think it’s ethically wrong in the slightest. If you own the DVD you have given the copyright holder due compensation; I think it’s ethically fine to make a backup of media that you legally purchased.

I was just saying that I don’t think it’s actually legal to do so for a DVD since those usually have CSS encryption.