After going multisig, it really makes a single seed phrase seem wildly insufficient for security...
If someone finds your seed, gg.
With multisig you can find all three of my seeds and still not even know which wallet it controls...
Discussion
SeedXOR, One Time Pads, and Passphrases are also options
SeedXOR looks cool, but it is not widely supported yet. It also doesn't offer any redundancy or allow for requiring multiple people to sign something. I'm not sure what the advantage is vs. multi-sig.
Passphrases are okay, but offer less security than mult-sig.
One Time Pads can be very secure, but are not standardized. They also don't seem to offer advantages over multi-sig.
It's target isn't to be better then multi sig. It's to be better then single sig without the complexity of multi sig.
It's more seed xor vs single sig and single sig with passphrase. Then seed xor vs multi sig.
I guess that makes sense. I'm still not convinced that ti's simpler, but I haven't tried it yet either.
Adding a passphrase (and storing separately) to a single seed phrase is an improvement without going full multisig. Might be a decent middle ground for some.
2-of-3 SEEDXOR
Also n-times more likely to lose 1-of-n