It doesn't matter how many private IP addresses there are, everybody has the same addresses. There are only 255 address in a range not 999 in any case. But there are more ranges than 182.168.1.nnn
The number of private addresses only restricts how many devices you can connect to one hub. Not many people have 250+ devices they need to connect.
A simplified guide to IP addressing
Also have a look at this: https://www.calculator.net/ip-subnet-calculator.html?cclass=c&csubnet=24&cip=192.168.1.255&ctype=ipv...
You can see the usable ip address range for this class of network. More info about the different subnets towards the bottom of the page.
Also this is for IPv4 there is also IPv6 which has been rolled out due to the Gloabl IPv4 address exhaustion but don't worry about that as it's slightly more complex and well much longer addresses.
You are totally missing the point.
There are millions of people whose devices have the address 192.168.1.1 but only you have your public IP address
There are countless John Smith's in the world, but only one John Smith lives at 1 high street, anytown
Thank you all for your help. The links helped explain it too. Cheers.