If you want to be multihomed, you need at least a /24 for your routes to be widely propagated. You can't simply announce a single /32 to multiple upstreams.
IPv4s are absolutely needed if you're an ISP/hosting provider or if you run something else than HTTP where there's no concept of "Host" header and it's assumed that 1 IP/port == one instance of the server.
I think your wish is that client applications (like browsers, and other client applications) embraced SRV records. I do not believe the protocol itself cares about your DNS lookup.
Anyway, there is absolutely no real value in IPv4. You should always be able to find a small chunk somewhere. A proxy will work wonders with one IP.
Lack of imagination, or expertise will make IPv4 very expensive when it becomes scarce but unlike a diamond ...