I think NEO could be such a competitor, offering rather quick and fast transaction. It is more used in the ICO transactions these day, so we will see how it grows in the future.
If NEO will be able to make more progress and gain more new tokens to use their platform there's high chance to compete with ETH and with how
investors gain from holding this coin will attract more investment, but as of now the value is still down and even there's already ico who uses thier
platform still not enough to be close to ETH success.