Not really that many
Back in 2011, before IANA ran out, we were going through more than one /8 per month. Three /8s sounds like a lot, but it's only a few months of global demand... and that's at 2011 levels. The internet has gotten bigger since then, and a lot of people are running low on addresses.
Of course, these addresses are restricted to just the APNIC region rather than being a global pool, but on the other hand it sounds like the majority of them still belong to someone and they'll just be asking politely if those owners would like to give them up, which many might not.
This isn't going to obviate the need to do IPv6.