I think it does matter, but it's good to be realistic about it.
If the availability of your application over the internet determines your revenue flow, you probably do want to try your best to make it as reliable as practical. Creating a mesh network to serve a large website is overkill, cost-wise. So you do what you can, and then you implement things like continuous integration, monitoring, trending, alerting and escalation procedures to be ready for the eventual failure.
In my experience, relying on a service provider designed to increase reliability (let's say Akamai) will smooth out the great majority of problems a live website might have with availability. One really reliable datacenter will keep the big problems at bay, leaving you to get good at iterating over common minor issues like maintenance and local performance issues.
If the availability of your application over the internet determines your revenue flow, you probably do want to try your best to make it as reliable as practical. Creating a mesh network to serve a large website is overkill, cost-wise. So you do what you can, and then you implement things like continuous integration, monitoring, trending, alerting and escalation procedures to be ready for the eventual failure.
In my experience, relying on a service provider designed to increase reliability (let's say Akamai) will smooth out the great majority of problems a live website might have with availability. One really reliable datacenter will keep the big problems at bay, leaving you to get good at iterating over common minor issues like maintenance and local performance issues.