We basically hit an ATH of difficulty last week.

Pretty sure that flood in China only affected the SHA256 ASICs which are only used to mine Bitcoin and Bitcoin Cash. However looking at the hashrate charts, it doesn't look like anything too drastic happened.

The difficulty for ETH will keep increasing since people are getting weeded out of mining ZEC due to the ASICs. Many 1080Ti's are going to switch to ETH in the next coming weeks since ZEC is no longer profitable for those GPUs.

Same reason why the XMR difficulty will keep increasing since many of the older AMD Radeon GPUs are switching from ZEC to XMR since the profits are identical but it uses less electricity.