Are "streamers" the new "transports"?

I’d add the Innuos Zen Mk.3 ($2600) to your list of candidates.  I like that it has a CD drive that let’s you rip your CDs right into its onboard memory — very easy and convenient.  Watch Darko’s video review of the unit where he compares to other streamers and also gives some explanations for why streamers make a difference.  I found it fairly interesting having not read much on this topic before.  FWIW. 

I heard a noticable improvement in SQ when I moved from a Wadia 3200 transport using coax to DAC,  to ripped CD's on a Windows laptop feeding the DAC over USB.

When you get to sourcing digital data from the Internet and sending it over USB to a DAC, it's incredibly, unbelievably cheap and reliable. We're talking $5.00-$10.00 components in a teeny weeny box, but you need a user interface, which could be a phone, tablet, or desktop.

Moving an analog signal from spinning vinyl to an amplifier is very difficult and always falls short of perfection.  Perfection in moving digital data from Internet to a DAC is not that hard with today's commodity technology (assuming adequate bandwidth).

Absolutely yes, with the same issues regarding the digital output plus the usability due to the app for the control of the player. Bluesound app is very good, Aurender app is good too but both are somewhat limited (not so for most of the users but I am quite nitpicky on this regard). 

My system is streaming based, I have an Aurender N10 streamer connected via AES to my DAC. Using a dedicated streamer absolutely a huge improvement in SQ and indeed its highly recommend if you wish to depend on qobuz and tidal.
What i have recently discovered and its quite shocking, but hearing is believing, and some of these tweaks are cheap to test, is the quality of your ethernet makes a substantial difference. 

First of all, forget Wifi. Your streamer must be hard wired using ethernet. That's why some streamer don't even have Wifi option.
Start with your typical three in one commercial "router" like Asus, netgear, tp link etc. These are a router + a switch + wifi hub all in one. Get a cheap router only, from a company like Ubiquity, like edgerouter x. we are talking a 150 USD investment here only. Create your internet connection within the new router, connect your streamer directly to it. Then you can use your old router as a wifi hub only (for your regular usage and also for your controlling device to see your streamer on the network).
If the improvement in sound of eliminating wifi circuitry interference from your main router doesn't shock you, i don't know what will!!
If that cheap step proves to you SQ improvement is possible through 'cleaning' your ethernet, you can try other steps such as adding a level of optical ethernet converters for further isolation (also relatively cheap). Then for a final icing on the cake, you can get a fancy ethernet switch from likes of Sotm or uptone. This is an expensive step, but after trying the earlier cheap ones, you might want to stretch to this. Naturally, high quality shielded ethernet cables like AQ vodka or Sotm make a difference as well. 
I believe we are still scratching the surface when it comes to digital music playback. But its fascinating how such services like qobuz and tidal could sound almost as awesome as a CD transport if used with a proper chain of playback. Starting from your router.