I don't know much about how BTC or ETH works, but why all cryptocurrencies takes so long to confirm a transaction. I think even 30s is too long, why cant it be instant like PayPal?
Congestion, that's why we are having a very long confirmation for our transactions. I'll give you a very easy example, if you are in the drive-thru of Mcdonalds and there are 5 people in-line, so you have to wait for a longer time right? And miners are giving those transactions priority that has higher fees. With PayPal, it's an instant, it also happens when you send bitcoin from the same web wallet bitcoin address.