I've been thinking about the same for a while: Can bitshares survive the EOS and other dex developments?

I think it can, especially because Dan seems to find it important. Unlike his withdrawal from steemit, he still mentions bitshares in his blogposts on Medium and has mentioned countless times that there will be some sort of beneficial co-existence between the two if not outright bts participation EOS (even though that's probably not up to him anymore).

So I think steemit will end up as myspace (the cool place people don't use anymore), bitshares will end up as youtube (the place you go to for everything) and EOS/block.one will end up as google/alphabet (the innovative, superrich and playful owner) if you get my analogy.