My experience is a little different from yours. Yes the new RPi board is significantly better than the earlier versions. Of course, it should be, it is quite an upgrade from previous versions. I find the Rpi wifi to degrade SQ compared to a wired connection. I can detect no difference in SQ whether I play back files from a NAS connected to my router, or a memory device connected to the Rpi. However, I tried a Samsung SSD and found it to be less clear than the micro SD cards that I use with a USB adaptor.
My biggest difference from your findings concerns Tidal. I find the SQ to be excellent. However, I am using Audivarna to upsample the Tidal stream before it goes to the Rpi and then to my Caiman DAC. The SQ is ultra smooth and very analogue. When upsmapled to DSD 128 or DSD 256, the sound I am getting from Tidal is amongst the best I have heard on my system.
Geoff
BTW; I did use Bubble PnP for a while. It is very user friendly and flexible but not a patch on the Audivarna for SQ or user interface.