Sorry to gang up, but I will third this.
I think most of us have upgraded our source last, if not completely ignored it at all. I used to think source meant DAC, as I was also one that invested heavy in that, but it comes before that!
I think my issue, probably similar to most, is that I saw the electronics as components with a purpose. DACs translate my digital, hopefully with minimal noise. Amp makes things go loud. Speakers/headphones makes the music go to my ears. Why the hell do I want a glorified computer (streamer) or WalkmanTM (DAP) if my PC or phone can already do that job???
I didn’t understand the whole source and downstream terms that people used to point out until I thought of the whole thing like a stream of water. You want to keep the water from the source as clean as possible until it reaches you. Things will inevitably taint the water – that is noise in this analogy. A PC or a phone is shitting in the water before you even start. When I finally got a proper streamer, I actually thought I got a brand new DAC. It makes that much of a difference and it makes sense now.
I hope that analogy helps and sorry again to gang up. I hope this helps others too.