[waibelp]

Welcome to dependency hell! Working for years in different "php environments" I learnt that most (web) developers I met in this field tend to use as much new fancy tools out there without thinking about business value and longterm impact. At the end of the day you might end up with more than four dependency systems...

To respond to your initial question if we really need so much dependency systems: No, we don't need to!

As the author already needs to use composer to set up PHP dependencies why not use composer for the other packages required? It's not a problem to get the common needed libraries via composer which dramatically reduces dependency complexity, deployment and build scripts because you don't need that much tools.