It's getting pretty expensive to rent one IPv4 address per domain these days. You also don't always control every address in a block, which means there may be nothing you can do about your reputation no matter where you go.
SMTP and SIP are often held aloft as fucked up. My Dad's home telephony runs off a RPi and a Yealink DECT station and a dynamic DNS.
The modern internet might look a bit fucked up if you only look at the X/Facebook/webby wankery stuff but the real internet is functioning quite happily.