According to
https://bitcoinfees.21.co/, it needs 420 satoshis/byte to get fast confirmations. Anyone know why the fees are going higher and higher?

This happens when there are a lot of unconfirmed bitcoin transactions. As of right now, there are over 200,000 unconfirmed transactions. You can check for yourself here:
https://blockchain.info/unconfirmed-transactionsThe more transactions there are, the higher recommended fees are going to be.
That's why.
Well that might as well ruin bitcoin. Since there a lot more people joining in by every day and in a a few years we'll be paying fees high as with fiat money.
The bitcoinfees.21.co website, and mostly everyone's brain, is broken.
Look at the graph on bitcoinfees.21.co, it's pretty clear to see that 120 satoshis per byte is what you need to pay, no different to last week. Or last month.
I've made a transaction with 120 sat/byte and I got 0/3 confirmations for 16+ hours, untill someone suggested me to use viabtc. So no, it's not.