recently, I was in an email thread where we had someone ask about dependency on XYZ.

I think this is an area, where much like the conservation of energy, you can shift the dependencies around - language, tool, framework, operating system, vendor, systems integrator, hoster etc - but at the end of the day you still have dependencies.

You are better off when you are aware of the dependencies - the unknown dependencies are the ones that are going to be expensive to deal with. I would recommend investing on a real options analysis if you are looking to add some rigor to your dependency analysis - just be aware that there your solution always has dependencies.