Just my perspective as a controls (SCADA engineer):

I work for a large power company. We have close to 100 sites, each with hundreds of IP devices, and have never had a problem with ipv4. Especially when im out in the field I love being able to check IPs, calculate gateways, etc at a glance. Ipv6 is just completely freaking unreadable.

I see the value of outward-facing ipv6 devices (i.e. devices on the internet), considering we are out of ipv4s. But I don't see why we have to convert private networks to ipv6. Put more bluntly: at least industry, it just isn't gonna happen for decades (if it ever does). Unless you need more IPs it's just worse to work with. And there's a huge amount of inertia- got one singular device that doesn't talk ipv6 at a given generation site? What are you supposed to do?