I'm not completely disagreeing... I've worked on pipeline transformers in node where I exposed gc and ran it after each item in the pipeline was done. It would grow insane without it... likewise I can see that if you're transforming a lot of records for delivery in PHP it could bloat as well.

However, if you're handling requests well within a given memory threshold, it isn't always something you should worry about until it becomes a problem. In which case, you'll probably want to look at something like go, rust, erlang or others to handle improvements, or break off heavy parts into sub/micro-services.