Ethereum is also slow right now because of just one game and talking about bitcoin it is getting lots of transactions because of increased demand for bitcoin.

Some are cashing out their bitcoin so they are moving their coins to trading platform to trade while many others are buying bitcoin and moving their coins out of the exchange to keep safe. All this is normal during huge price movement both pump/dump.

When we will have lightening network on bitcoin we might not have such issues because of off-chain transactions.