SLA numbers are not insurance. At best, they give you back some of your hosting costs... but if you are doing anything serious? that's a very small fraction of what you lost due to the downtime.
Also, 'uptime' means a different thing on a VPS than in a cloud. In a cloud? if a server goes bad, you shoot the server and the customer spins up nodes on another one. the local data is gone. This is not counted as downtime.
On a VPS? that's counted as downtime and as data loss.