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?
BTC transactions are actually INSTANTANEOUS. It's confirmations that take a longer time (10 minutes) because that's how Bitcoin works.
Bitcoin has a block time of 10 minutes and that amount of time was chosen presumably because it is a good compromise of speed, security and bandwidth.
The Lightning Network will allow for instantaneous, off-chain transactions that will not need to be confirmed.