Lots of good common sense advice and practical experience there. I've had my fair share as a devops/sysadmin working on crazy systems (more worse than better haha). So it's unsurprising how common sense isn't always put into practice.

I do believe caching to be the proverbial Swiss Army Knife of performance. Some of its tools can be used properly and others as band-aid / stop gap. Even band-aids serve a useful purpose. But I can definitely see how a system can accrue technical debt when over leveraging caching.

But to believe in prevalent, perfectly built systems is to deny the status quo of the landscape. When you democratize development like WordPress has done with its plugins and Node has done with npm, as popular examples, you definitely have it coming.