Why a dedicated SACD player more noticeable sound quality difference than HDMI-I2S w/ DACs

I Donot agree with that.

if you properly remove weak links in your digital chain ,and provide Quality 

Digital is best in many areas. In our large  audio group I have see. Most everything 

out there.  From you router that cheap noisy wall wart ,get rid of ,replace with much lower noise LPS ,linear tube audio makes a great one 

quality Ethernet hub at minimum $600 LHY  SW8: if you can afford better $3k substantial improvement Danish Audio group, or Innuos, quality Ethernet cables 

put best one at end point ,and a quality streamer with a LPS ,Dac needs to be at minimum $2k on up . Then you will hear a substantial Digital experience quality power cords also a must .

My statement is not about A is better than B.

Our observation is that a dedicated new SACD player has more audible sonic differences than simply adding different external DAC (in this case thru HDMI-I2S adapter) to existing SACD player.

So was curious whether anyone has observed the same or have knowledge as to why that is.

I just replaced an OPPO 103d I was using as a "transport" with a dedicated transport , the Teac VRDS 701t .  Night and day difference,  no comparison. 

Wish I had done this a long time ago.  The difference is not subtle , the OPPO was poor as a music transport.