The high price is due to the fact that there is a lot of demand. And as we know from the lesson in economics, the higher the demand, the more supply. And of course the price will be high. Everyone uses it and wants to use it because of its simplicity.
that's why ethereum is not over priced. I have been thinking about that too and this time ethereum grows steadily. People should aware about that dude.
People are using it caused by they can get a lot of advantage from it and the majority of defi projects were also using ethereum. It's not only the ethereum community but so many icos and ieos that used ERC20 were getting a lot of usefulness from the ethereum EVM.