I'd hardly say 5.45 is dead...
Just that there's 'Russia' and 'Everybody Else'
The Russians never widely exported their 'top end' equipment...
7.62x39 is so widely used in the left-over world simply because once Russia switched, what better to do with the old stuff than sell it?
China is abandoning 7.62x39 for their own home-brew 6mm cartridge, and the statement will continue that the only countries who use 7.62mm for a standard issue cartridge either do so because there's nothing else they can afford, becasue it was given to them back in the Cold War for free/cheap, or are in the process of switching to something else...
Note that the Iraqis (government type, not terrorist type) want to 86 7.62x39 for 5.45 or 5.56...
It's a small-caliber world out there - at least when it comes to major powers...