“Your own server in a colo” means going to the colo to swap RAM or an SSD when something goes wrong. You rent a server and the benefit is the rentor has spare parts on hand and staff to swap parts out.
You can also pay smart hands to do that. My experience with Equinix for example it's been great.
So on average once or twice per 5 years per server. Remote hands are also service you can pay for.
Most expense is initial setup and automation, but once you get thru that hump and have non-spiky loads it can be massively cheaper