I personally believe that a lot of things are going to gravitate into bitcoin, and they are not necessarily going to be built on bitcoin right away, but frequently, there are people who say that they are working on a lot of projects that are on various shitcoins, including the amorphous defi concept, but their purpose is likely NOT so much about building upon a secure system, but instead engaging in some kind of means to print money or to pump and dump and they do not care if their system is secure.
Sure, everyone needs to put food on their table, so I cannot really blame people for wanting to make money through whatever work they are doing, but I, personally, see a lot of seeming phoney baloney in the various systems that are built on ethereum,
I don't know if it will really be "a lot of things". There might be a few innovations we can incorporate, but there's so much gimmickry in the market right now that it almost seems to drown out anything that might actually be revolutionary. Quite a few people talk about altcoins in terms of faster/cheaper transactions, but I think their greatest purpose is to field-test all the weird and wonderful ideas people come up with and hopefully screen-out the failed ones. Then, on the rare occasion one of those features is a net positive and provides some additional utility that people actually benefit from, it's something we can potentially look at building on top of Bitcoin. Assuming it doesn't compromise any of the existing qualities people like, that is. So generally, I'd expect
some new features built on top, but not that many. Then again, who knows what the future holds? I could be way off, heh.