There is never going to be a unicorn. MLS is good but there will definitely be better things.
Discussion
Which is why I hope that developers continue upgrading and implementing these new specs as they get built and released. Otherwise we'll have 20 clients with 10 different DM methods, making a huge headache for users.
My point is that we shouldn't just dismiss the state of DMs as you suggested in the first reply. Devs should implement NIP-17 as it stands today even though NIP-104 is in the horizon.
Considering that NIP-17 took about 1.2 years to be developed, audited, implemented by 2+ clients and merged, MLS will take another year to be ready.
It is worth noting that even with MLS coming out, NIP-17 may still be the preferred DM type because it supports device synchronization, whereas MLS does not.