To add a counterpoint to your evidence, I think an important part of why full-stack tends to be a thing and that front-end / back-end silo less than other disci

To add a counterpoint to your evidence, I think an important part of why full-stack tends to be a thing and that front-end / back-end silo less than other disciplines like infrastructure and security is that front end and back end developers more often have a symbiotic relationship. In a fully siloed world, where front-end developers never touched the backend and vice versa, both groups would be completely unable to deliver value or do much of anything useful on their own. That's definitely not true of the examples you provided.