Best practice DMZ (public or private IPs)?

So I just had a chat about what IPv4 range sould be used for a DMZ. In the last few years I've seen and built a lot of public IP DMZs. I only resorted to NAT when there were limited public IP addreddes available. Today for the first time after years I was told I should build private range DMZ with NAT again like they were built years back when IPv4 adresses were expensive.

Maybe I am outdated on that matter.

Big public IP range available. DMZ contains SFTP and FTPS servers, several web servers as part of webapplications and customer portals, mailrelays, IAM servers and VDI connection servers.

What is your take on this and why?

Thanks so much in advance.