“And I’m not talking about streaming and such, because that is relatively young in its development.”
This would be incorrect as i have been streaming over 10 years now. I bought my first streamer from Aurender in 2011. The market is now flooded with streamers and servers at all price points. As far as DAC goes, a high quality DAC from 10 years ago is just as relevant today. The newer DAC certainly improved in the areas of noise isolation, jitter, clocks, power supply and chips. And accept higher resolution upto DSD1024.