IMHO after a certain point the effect of the next best cable on the market may give you a 0.1% improvement in apparent sound, which may be a change in the sound perceived, or an actual improvement. There is only so much that can be done that will withstand the cost/benefit equation.
Not all new wiz bang components or cable will give the improvement for the cost. I can only opine that enthusiasts may change for changes sake, components and circuitry become obsolete or die, or there is the look at me value.
Once a level of equipment has been reached, it falls back to what you can do with the room up to a certain point where you are happy.
I have a nice system that has served me well in between my work and family. I am in a fortunate position that, not only we are building our new (and hopefully last) home with a dedicated music room that I have had designed (within a budget) but will enable me to tune it.
This has also triggered a complete new system (sanctioned by my most important person) and I have quietly been accumulating valuable knowledge on this and other forums. I have all the experience of others to use, and that makes my decisions easier in that I have a solid benchmark available.
So a big thank you to all forum contributors who have spent time to write of their experiences and at times jousting of opinion. It's a very healthy community.