It's pretty rare that you would need more than one.
If you're running different types of services (e.g. http, mail, ftp) then they each use their own ports and the ports can be mapped to different local machines from the same public IP address.
The most common one where you're likely to have multiple public services using the same protocol is http[s], and for that you can use a reverse proxy. This is only a few lines of config for nginx or haproxy and then you're doing yourself a favor because adding a new one is just adding a single line to the reverse proxy's config instead of having to configure and pay for another IPv4 address.
And if you want to expose multiple private services then have your clients use a VPN and then it's only the VPN that needs a public IP because the clients just use the private IPs over the VPN.
To actually need multiple public IPs you'd have to be doing something like running multiple independent public FTP servers while needing them all to use the official port. Don't contribute to the IPv4 address shortage. :)
It's pretty rare that you would need more than one.
If you're running different types of services (e.g. http, mail, ftp) then they each use their own ports and the ports can be mapped to different local machines from the same public IP address.
The most common one where you're likely to have multiple public services using the same protocol is http[s], and for that you can use a reverse proxy. This is only a few lines of config for nginx or haproxy and then you're doing yourself a favor because adding a new one is just adding a single line to the reverse proxy's config instead of having to configure and pay for another IPv4 address.
And if you want to expose multiple private services then have your clients use a VPN and then it's only the VPN that needs a public IP because the clients just use the private IPs over the VPN.
To actually need multiple public IPs you'd have to be doing something like running multiple independent public FTP servers while needing them all to use the official port. Don't contribute to the IPv4 address shortage. :)