Security - not really, but to be honest CG-NAT is kind of nice for privacy. I don't have to worry about leaking a (by default) permanent identifier. Once/if I go full ipv6, I'll probably start using a VPN full time.
For law enforcement purposes most CGNAT operators should keep a log of who had what address at what time. You can still get blocked by websites until you get a new address, though.
AFAIK it is within the same /64, which for all tracking purposes means "the same ip". The CG-NAT ip on the other hand is not even unique at any particular moment, let alone permanently. Kind of like having your own free residential VPN.
