you are seeing these problems because Ethereum has a lot of issues and bugs and it can simply go down like this. it has happened before multiple times. each time it was as long as a week before going back to normal but it will get worse as it grows. which is partly due to its scaling issue.

some people think just because some altcoin has faster blocks and seemingly fast transactions, it is a good thing but they miss all the long term downsides such as what you are experiencing here.

it won't fall now because the issues are not yet serious and also because the whale manipulators still want their profit out of this coin and they won't let it burn that easily. but it is a doomed project that will fail miserably in the end. and there is no stopping that.