How are most audiophiles going from streamers to DACS

I2S or AES/EBU. Metrum Acoustics Ambre streamer to Pavane DAC

The Node 2i does not have USB output. The new Node spec page claims that the USB-A jack will be an output in a future software update, which has not occurred yet to my knowledge. At present it is only an input, same as in a Node 2i.  That said, I use an AQ Coffee 1M interconnect from my Node2i to my Mytek Liberty and that clearly beat out the BJC and Transparent Performance coaxes used previously…both much less $$$ than the AQ.  At least I think so!

I still use a Node2 in my second system connected to a Benchmark DAC3 using coax with good results.

I have a bluesound. I think the streamers that have USB are higher $$. Your streamer and DAC will give you satisfying sound. I am using a COAX, this is what is most common.

for the new release bluesound node, the usb digital output that is coming will satisfy some users who like that connection interface

i have had very good results using spdif digital out from the node 2i... since late 2019 i tried and compared it to much pricier streamers from auralic, aurender, innuos, mytek, and using them as streamer only (not their dac outputs) with their suggested output connection, i did not hear a difference in sq

in theory, the spdif format slaves the downstream dac to the clock of the upstream streamer, whereas usb 2,0 will allow the dac to slave the server... but if the sending unit clock is sufficiently stable and does not introduce jitter (and the connection length does not create reflections), the bitstream can and will be properly received at the dac using spdif