I think you've hit at the heart of the problem, but swapping the DevOps model for SRE is robbing Peter to pay Paul. Last place I worked with a 100+ person tech

I think you've hit at the heart of the problem, but swapping the DevOps model for SRE is robbing Peter to pay Paul. Last place I worked with a 100+ person tech team had more of an SRE model. The SRE team were charged with reliability. They had no incentive to delivery features or to improve developer experience. As a result, developer tools sucked, there was s rigid release schedule, every bug was met with a rollback. This was probably an extreme case because the team was also not very good, but either way it was a clear case of misaligned incentives. The entire point of DevOps was collective ownership with a shared goal of customer value that is function of feature richness, quality and reliability. It's the Holy Grail of efficiency, it's just really hard to build that kind of culture.