You are right, IPv6 was meant to solve the address depletion issue but it is extremely hard to get people to move to it. IPv4 is just what everyone knows and understands so they are trying to cling to it as long as they can. The main reason is addressing.

An IPv4 address looks like this 192.168.45.10, I guess you know that. An IPv6 address looks like this: 2607:f0d0:1002:0051:0000:0000:0000:0004

I can be shorted so the zeros are removed but it still looks like this:

2607:f0d0:1002:51::4

Then there is the problem of interconnecting Ipv4 to IPv6 networks, IPv6 is not backward compatible with IPv4 so you need to translate between the two and run both stacks on every router.

So people have spent effort in to delaying it, for example many mobile carriers run NAT between the mobile network and the Internet. If they didn't we would have been out of IPv4 addresses years ago because of smart phones.

So has anything happened in the last 10 years? Kind of, service providers are almost all running IPv6 in their core networks and many will give out IPv6 addresses on request but you generally need to ask for it. In the corporate world, mostly the same as things were 10 years ago, it's seen as an unnecessary change and I doubt many will even bother.

Yeah, IPv6 is basically free. The trouble is adoption is still not that great. I think all major wireless carriers use it now for mobile devices, so that should be good enough for most of us.