Good breakdown - even as DEXs improve it will be the third point that dictates the migration to using them.  The interfaces will eventually be pretty and the word will get out about using a DEX.

People will need to get of their butt so to speak and make the change themselves though.  No central entity to push it on them or say this is the software you should/need to use now.

Thanks for listing the DEXs, was only familiar with bitshares.