Maybe you don't need SRE?

Is this what people think sysadmins and operations do all day? Any place i've worked with an operations team, they were the group deciding on datacenter sites, switches, routers, architecture, operating systems, configuration management, monitoring, services like DNS, dhcp, network security, access control, on-boarding / off-boarding, etc. If you weren't in operations you didn't deploy or make decisions on production changes. At a few other places this was split into an operations and infrastructure groups that worked closely together as they had to plan EOL replacement and new build-outs together.

"Wisdom arrives to anyone exposed to how systems behave. SRE shouldn’t rob developers this learning opportunity."

SRE has always seemed to just be a push for a dedicated sysadmin that can read/write code to support a specific application in production. As noted in the quote above, you can just replace SRE / developers with development / operations. Its the same circle all over again.

Lastly, on-call is just companies being cheap. For startups this might be a good initial solution but for anything that has to be online you should have 24/7, follow-the-sun support teams. This allows for teams to solve problems within their normal work day and not have someone up all night to fix a problem, brief everyone on the issue, and then if they are lucky have the next day off.