Leasing brings extra security:
Waves can't can't be spent as long ad they are leased
LolWaves can't can't be spent as long ad they are leased
It takes 10 seconds to unlease them.
What would bring a layer of security is 2fa. It is very suprising this is not implemented yet.
They only unlease and are back in your wallet after the next block, not 10 seconds.