Do I really need a separate Roon Core (computer) to use Roon Software?

The way I understand it, there are basically 4 devices required to use Roon software to play digital music files (whether from local file storage or streaming). 1. The Roon Core on which the software is installed. 2. A streamer, which takes the datastream from the core (via Ethernet) and provides a high quality input to the DAC. 3. The DAC. 4. And finally an optional controller such as a smartphone or tablet. Seems like a lot of hardware. 
Many people rave about Roon being so fantastic, but is it really worth adding another piece of hardware, power supply, power cord, interconnect, and ongoing maintenance of that hardware?

Currently, I have a LUMIN D1, which is a streamer DAC combo, and I like it. But I’m wondering what Roon would bring to the party.

So my second question is: Is there any hardware that includes the “Core” within the streaming device instead of requiring a separate piece? I found the ELAC Discovery DS-S101-G, but it does not include MQA nor Qobuz, and seems to be obsolete already. I’m kind of old school, and prefer the one box solution for sources. I’m not interested in hooking up a computer to my rig either.  Thanks in advance for any wisdom or advice!