Most sites hosted on cPanel are relatively small and never need to horizontally scale. People running apps large enough to require multiple servers usually try to optimize their environment by reducing overhead (and cPanel adds quite a bit of it) and tend to not need a GUI for server admin.
and most every cpanel (and every other web host panel) box on the planet.
web, ftp, database, mail, dns, and more. all on one machine.
Most sites hosted on cPanel are relatively small and never need to horizontally scale. People running apps large enough to require multiple servers usually try to optimize their environment by reducing overhead (and cPanel adds quite a bit of it) and tend to not need a GUI for server admin.