Okay, I see a need for an example.
If I decide to provide shared hosting, I can rent one server from OVH/Hetzner/anyone, SSH in, install cPanel, setup packages and pretty much leave it running in autopilot mode. The support doesn’t have to be great, it’s a cheap service and people expect that not everything will be perfect.
//EDIT: As mentioned, CloudLinux will effectively prevent one client from bringing down the whole server as well. Less things to worry about
In the meantime, if I provide dedicated servers:
If something breaks, I have to stop doing whatever it is I’m doing, drive to the datacenter, troubleshoot and fix/replace the hardware (which costs money). This all has to be done in a timely manner (hours maximum).