Well it depends on your tradeoff decision between SLAs & Development productivity.
If you hire explicit 20% staff to do operational tasks, and also wall off a fixed rotating 5% of your dev team to assist them.. then you've made a conscious decision on resource allocation of 25%. If the other 95% of the dev team is getting interrupted every 30minutes by "questions" then your operational staff/rotation is not resulting in better runbooks, etc.
If you want better SLA and your operational staffing is not sufficient, then you should see your SLA breach, make staffing/process changes, etc.
When development just papers over these issues you end up with great operational metrics and bad development metrics, so then everyone can be even more upset at dev!
If you hire explicit 20% staff to do operational tasks, and also wall off a fixed rotating 5% of your dev team to assist them.. then you've made a conscious decision on resource allocation of 25%. If the other 95% of the dev team is getting interrupted every 30minutes by "questions" then your operational staff/rotation is not resulting in better runbooks, etc.
If you want better SLA and your operational staffing is not sufficient, then you should see your SLA breach, make staffing/process changes, etc.
When development just papers over these issues you end up with great operational metrics and bad development metrics, so then everyone can be even more upset at dev!