100% spot on. I've been through this a couple times. I'm all for polyglot systems when it makes sense (ie data science may expose its work in function or services written in python, product teams may use javascript for the isomorphic benefits you mentioned). But I can't think of a case where PHP make sense. Performance? No. Language features? No. Ease of deployment and configuration? No. Exactly where does this language excel or offer an advantage?