Stablescoins, ICOs, IEOs, SEOs, Defi will be built on Ethereum.
IEO on Ether? Where does that happen? IEO is a tool for an exchange to pump their own token, so it's not Ethereum exclusive.
On top of that, Ethereum competitors are growing rapidly. I'm not sure if ICOs will stay either, considering how scammy they were in 2018. Holding Ethereum is good for short-term, as long as nobody realizes it's supply and crazy premine.