[9dev]

DHCP requires explicit configuration; it needs a range that hopefully doesn't conflict with any VPN you use; it needs changes if your range ever gets too small; and it's just another moving part really.

With SLAAC, it's just another implementation detail of the protocol that you usually don't have to even think about, because it just works. That is a clear benefit to me.

[j16sdiz]

When it fail, you find there is no option to tune its behaviour.

Plug in a rough router and see quickly you can find it.

[9dev]

What kind of failure are you referring to? What would you want to tune? You can still easily locate all devices on your network.