Ethereum is still at its best, dominating the dapp market in 2018. It gains the highest active number of dapp users among others. Not just that, its leading the market also in terms of wallet holders and total number of dapps.
But despite of the stable growth, Ethereum may find 2019 a tough year to begin with. Aside from the less transaction it has compared to the others, its dapp users needs to maintain an ETH for the gass fee every transaction. This greatly affects the dapp users experience and full mass adoption of Ethereum Dapps.
This is something an Ethereum dapp must consider and/or think about this year.
Source: https://www.dapp.com/article/annual-dapp-market-report-2018?utm_content=Vale more than challenge there is some development will definitely needed here otherwise that trust of investment in Crypto of field will be reduced if the demand was reduced then people don't have value for the existing investment so that will be a lots of problems will happen if this year will not helpful for the development of ethereum that's why it will be more challenging.