In an organisation of any significant size, remembering legacy IP is much worse than v6.
Chances are you will have lots of disparate legacy blocks, some starting 1.x, some starting 80.x etc. Then you have all the RFC1918 space, and the possibility of overlapping address space in different areas of the business. Then you have to keep track of translations, so an internal address 10.1.1.1 could have an external address of 80.1.1.1 but only on port 25, if you're talking over port 443 then actually the traffic is forwarded to 192.168.1.1 instead.
IPv6 is simpler. You have a single prefix for your company, eg 2001:db8:: Then you split it out in a sensible hierarchical way, for instance 2001:db8:1:: is your facility in the US, 2001:db8:2:: is your facility in Canada etc. Beyond that you go down to VLANs and hosts as needed.
So 2001:db8:2:25::1 is a device in your toronto data center... 80.1.1.1 is where?!?!? 192.168.1.1 is where?!? and which one did you mean?!?!
Then there's no NAT, no address overlap, much simpler. 2001:db8:2:25::1 is the same device wether you're talking to it on port 1 or port 65535. Your firewall rules are simpler and more secure as a result.
Microsoft had a presentation about this, and they are a bigger organisation than most.
If you're only small then you don't care, technologies like SLAAC and MDNS exist for exactly this reason.