I assume you don't mean private space, as my current configuration actually relies on it being so diverse. For example running more than one VPN instance with a low chance of both using the same IP range.
Microsoft had to migrate to IPv6 before everyone else as they literally ran out of IPv4 private addresses, though I guess there's not many corporations large enough enough to run into that problem.
I wasn't, no, I used the word 'reserved' carefully, though. There are a large number of v4 addresses reserved and doing nothing.
On the wider point if your home and private servers require 10/8, 172.16/12 and 192.168/16 in their entirety and diversity you may be using excessively large subnets. Unless you're running a business involving VPNs or giving access to your data to the public in some capacity you can happily use /28s or /29s to reach home, smaller the subnet lower the chance of overlap.
CG-NAT doesn't overlap with the RFC1918 address space it has its own, 100.64/10, and only needs to be unique per gateway.
Address overlap on larger networks is fine. This is why we have VRFs. There's a ton of overlap on cloud services but the routing tables aren't exposed to each other. There's a ton of address overlap on ISPs serving enterprises but it's for the most part fine as they're in different tables. On VPNs home routers almost always kindly sit in the 192.168/16 range so are easy enough to avoid.
