bitcoin has many technological limitations(1MB size of block, takes long time to process your transaction) and so had been hardforked to bch, btg.
it could only be used as currency since they do not support platform like ethereum does.
currently many icos are based on ethereums, cause they support tokens on their platform.
I think the only benefit of using bitcoin is that it is the very first cryptocurrency and altcoins are exchangeable in exchange because of btc's stability.
how do you think of bitcoin? will it still have much advantages&value as it now has?
I think bitcoin and all other cryptocurrencies can still improve, if not now, may be in the near future. We are entering an era of technological world and all cryptocurrencies will seems to be part of it. But for now, bitcoin, alts, and icos are very promising not just in currency function but also in the function of an asset in investment. Time will tell how their competition will end.