My journey in digital music playback without using physical media (i.e., servers, streamers, and digital conversion) has consistently become ergonomically easier to implement as well as better sounding. Every new DAC and every music server upgrade has been a notable sonic improvement over the previous. As mentioned by @sbank , improvements have been achieved by reducing jitter and noise; primarily through improvements in processing, power supplies, and isolation. The sonic improvements have consistently moved toward a more natural sounding presentation, improved dynamic impact, and better resolution without an accompanying hard edge.
Considering that I have consistently provided a baseline of stable, damped support, clean power, and adequately constructed digital cables, the notable sonic improvements have all resulted from upgrading to better equipment (servers and DACs). None of the add-on tweaks, filters, etc. that I have tried have made what I could reliably call a consistent sonic improvement, especially compared to the improvements resulting from upgrading my digital playback equipment. I appreciate the dedicated manufacturers who have researched and implemented improvements in their equipment to bring us better sound.